From 0cf5c04259dec946276c51999064252a3e4834a5 Mon Sep 17 00:00:00 2001
From: Jose Luis Blanco-Claraco <joseluisblancoc@gmail.com>
Date: Thu, 12 Dec 2024 09:07:58 +0100
Subject: [PATCH] mola-kernel Doxygen docs: add groups

---
 mola_kernel/include/mola_kernel/entities/EntityBase.h  |  4 ++--
 .../include/mola_kernel/entities/EntityRelativeBase.h  |  2 +-
 .../include/mola_kernel/entities/KeyFrameBase.h        |  2 +-
 .../include/mola_kernel/entities/LandmarkPoint3.h      |  2 +-
 mola_kernel/include/mola_kernel/entities/RefPose3.h    |  2 +-
 .../include/mola_kernel/entities/RelDynPose3KF.h       |  2 +-
 mola_kernel/include/mola_kernel/entities/RelPose3.h    |  2 +-
 mola_kernel/include/mola_kernel/entities/RelPose3KF.h  |  2 +-
 .../include/mola_kernel/entities/entities-common.h     |  6 ++++++
 mola_kernel/include/mola_kernel/factors/FactorBase.h   | 10 ++++++++--
 .../mola_kernel/factors/FactorConstVelKinematics.h     |  2 +-
 .../include/mola_kernel/factors/FactorRelativePose3.h  |  2 +-
 .../mola_kernel/factors/FactorStereoProjectionPose.h   |  2 +-
 .../include/mola_kernel/factors/SmartFactorIMU.h       |  2 +-
 .../factors/SmartFactorStereoProjectionPose.h          |  2 +-
 .../include/mola_kernel/interfaces/BackEndBase.h       |  8 +++++++-
 .../include/mola_kernel/interfaces/Dataset_UI.h        |  2 +-
 .../include/mola_kernel/interfaces/ExecutableBase.h    |  2 +-
 .../include/mola_kernel/interfaces/FilterBase.h        |  2 +-
 .../include/mola_kernel/interfaces/FrontEndBase.h      |  2 +-
 .../mola_kernel/interfaces/LocalizationSourceBase.h    |  2 +-
 mola_kernel/include/mola_kernel/interfaces/MapServer.h |  2 +-
 .../include/mola_kernel/interfaces/MapSourceBase.h     |  2 +-
 .../include/mola_kernel/interfaces/NavStateFilter.h    |  4 ++--
 .../mola_kernel/interfaces/OfflineDatasetSource.h      |  2 +-
 .../include/mola_kernel/interfaces/RawDataConsumer.h   |  2 +-
 .../include/mola_kernel/interfaces/RawDataSourceBase.h |  2 +-
 .../include/mola_kernel/interfaces/Relocalization.h    |  2 +-
 .../include/mola_kernel/interfaces/VizInterface.h      |  2 +-
 29 files changed, 49 insertions(+), 31 deletions(-)

diff --git a/mola_kernel/include/mola_kernel/entities/EntityBase.h b/mola_kernel/include/mola_kernel/entities/EntityBase.h
index 5947966a..80395bf1 100644
--- a/mola_kernel/include/mola_kernel/entities/EntityBase.h
+++ b/mola_kernel/include/mola_kernel/entities/EntityBase.h
@@ -23,13 +23,13 @@ namespace mola
 {
 /** Arbitrary annotated data, indexed by "label" or "variable name" and
  *capable of offline storage on disk when not used.
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 using annotations_data_t = std::map<std::string, LazyLoadResource>;
 
 /** Base class for all "entities" in the world model
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class EntityBase : public mrpt::serialization::CSerializable
 {
diff --git a/mola_kernel/include/mola_kernel/entities/EntityRelativeBase.h b/mola_kernel/include/mola_kernel/entities/EntityRelativeBase.h
index ddb1fc08..4db251bb 100644
--- a/mola_kernel/include/mola_kernel/entities/EntityRelativeBase.h
+++ b/mola_kernel/include/mola_kernel/entities/EntityRelativeBase.h
@@ -17,7 +17,7 @@ namespace mola
 {
 /** World optimizable entities which are relative to some keyframe.
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class EntityRelativeBase : public EntityBase
 {
diff --git a/mola_kernel/include/mola_kernel/entities/KeyFrameBase.h b/mola_kernel/include/mola_kernel/entities/KeyFrameBase.h
index 4386ff7a..6a1bbb72 100644
--- a/mola_kernel/include/mola_kernel/entities/KeyFrameBase.h
+++ b/mola_kernel/include/mola_kernel/entities/KeyFrameBase.h
@@ -25,7 +25,7 @@ namespace mola
  * This class is used as a base class for all world-model entities that can be
  * used as robot/vehicle keyframes.
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class KeyFrameBase
 {
diff --git a/mola_kernel/include/mola_kernel/entities/LandmarkPoint3.h b/mola_kernel/include/mola_kernel/entities/LandmarkPoint3.h
index 36456f61..f21180ae 100644
--- a/mola_kernel/include/mola_kernel/entities/LandmarkPoint3.h
+++ b/mola_kernel/include/mola_kernel/entities/LandmarkPoint3.h
@@ -18,7 +18,7 @@ namespace mola
 {
 /** A 3D point landmark.
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class LandmarkPoint3 : public EntityBase
 {
diff --git a/mola_kernel/include/mola_kernel/entities/RefPose3.h b/mola_kernel/include/mola_kernel/entities/RefPose3.h
index 54efc29a..63d8e367 100644
--- a/mola_kernel/include/mola_kernel/entities/RefPose3.h
+++ b/mola_kernel/include/mola_kernel/entities/RefPose3.h
@@ -21,7 +21,7 @@ namespace mola
  * relative maps (submaps). Global SLAM frameworks should have only one entity
  * of this class, submapping approaches will have several instances.
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class RefPose3 : public EntityBase
 {
diff --git a/mola_kernel/include/mola_kernel/entities/RelDynPose3KF.h b/mola_kernel/include/mola_kernel/entities/RelDynPose3KF.h
index ed1c7560..a2d857e2 100644
--- a/mola_kernel/include/mola_kernel/entities/RelDynPose3KF.h
+++ b/mola_kernel/include/mola_kernel/entities/RelDynPose3KF.h
@@ -21,7 +21,7 @@ namespace mola
 /** A relative "dynamic" pose: SE(3) pose + velocity vector.
  * Both the pose and the velocity vector are given in the frame of the base KF.
  * This entity is also a key-frame.
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class RelDynPose3KF : public EntityRelativeBase, public KeyFrameBase
 {
diff --git a/mola_kernel/include/mola_kernel/entities/RelPose3.h b/mola_kernel/include/mola_kernel/entities/RelPose3.h
index f13dcd31..c6328a01 100644
--- a/mola_kernel/include/mola_kernel/entities/RelPose3.h
+++ b/mola_kernel/include/mola_kernel/entities/RelPose3.h
@@ -18,7 +18,7 @@ namespace mola
 {
 /** A relative SE(3) pose (e.g. a sensor pose wrt the vehicle)
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class RelPose3 : public EntityRelativeBase
 {
diff --git a/mola_kernel/include/mola_kernel/entities/RelPose3KF.h b/mola_kernel/include/mola_kernel/entities/RelPose3KF.h
index 68ee459a..36a78c5c 100644
--- a/mola_kernel/include/mola_kernel/entities/RelPose3KF.h
+++ b/mola_kernel/include/mola_kernel/entities/RelPose3KF.h
@@ -20,7 +20,7 @@ namespace mola
 /** A relative SE(3) keyframe, holding a relative SE(3) pose wrt to the base
  * frame.
  * This entity is also a key-frame.
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_entities_grp
  */
 class RelPose3KF : public EntityRelativeBase, public KeyFrameBase
 {
diff --git a/mola_kernel/include/mola_kernel/entities/entities-common.h b/mola_kernel/include/mola_kernel/entities/entities-common.h
index 3593c9f2..58924bc0 100644
--- a/mola_kernel/include/mola_kernel/entities/entities-common.h
+++ b/mola_kernel/include/mola_kernel/entities/entities-common.h
@@ -21,7 +21,13 @@
 
 namespace mola
 {
+/** \addtogroup mola_kernel_entities_grp Centralized map database entities
+ *  \ingroup mola_kernel_grp
+ *  @{ */
+
 /** Placeholder for generic entity of user-defined types */
 using EntityOther = std::shared_ptr<EntityBase>;
 
+/** @} */
+
 }  // namespace mola
diff --git a/mola_kernel/include/mola_kernel/factors/FactorBase.h b/mola_kernel/include/mola_kernel/factors/FactorBase.h
index 6aa98396..5db1a0cc 100644
--- a/mola_kernel/include/mola_kernel/factors/FactorBase.h
+++ b/mola_kernel/include/mola_kernel/factors/FactorBase.h
@@ -17,8 +17,12 @@
 
 namespace mola
 {
+/** \addtogroup mola_kernel_factors_grp Centralized map database factors
+ *  \ingroup mola_kernel_grp
+ *  @{ */
+
 /** Defines a type of robust (m-Estimator) factor
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_factors_grp
  */
 enum class Robust : uint8_t
 {
@@ -32,7 +36,7 @@ enum class Robust : uint8_t
 
 /** Base class for all "factors" in the world model
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_factors_grp
  */
 class FactorBase : public mrpt::serialization::CSerializable
 {
@@ -73,4 +77,6 @@ class FactorBase : public mrpt::serialization::CSerializable
     void baseSerializeFrom(mrpt::serialization::CArchive& in);
 };
 
+/** @}  */
+
 }  // namespace mola
diff --git a/mola_kernel/include/mola_kernel/factors/FactorConstVelKinematics.h b/mola_kernel/include/mola_kernel/factors/FactorConstVelKinematics.h
index 94d30aba..42e27881 100644
--- a/mola_kernel/include/mola_kernel/factors/FactorConstVelKinematics.h
+++ b/mola_kernel/include/mola_kernel/factors/FactorConstVelKinematics.h
@@ -19,7 +19,7 @@ namespace mola
 /** Abstract representation of a constant-velocity kinematic motion model factor
  * between two key frames.
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_factors_grp
  */
 class FactorConstVelKinematics : public FactorBase
 {
diff --git a/mola_kernel/include/mola_kernel/factors/FactorRelativePose3.h b/mola_kernel/include/mola_kernel/factors/FactorRelativePose3.h
index e4348642..bf80f87b 100644
--- a/mola_kernel/include/mola_kernel/factors/FactorRelativePose3.h
+++ b/mola_kernel/include/mola_kernel/factors/FactorRelativePose3.h
@@ -21,7 +21,7 @@ namespace mola
 {
 /**
  *
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_factors_grp
  */
 class FactorRelativePose3 : public FactorBase
 {
diff --git a/mola_kernel/include/mola_kernel/factors/FactorStereoProjectionPose.h b/mola_kernel/include/mola_kernel/factors/FactorStereoProjectionPose.h
index 0261de22..20ea6fff 100644
--- a/mola_kernel/include/mola_kernel/factors/FactorStereoProjectionPose.h
+++ b/mola_kernel/include/mola_kernel/factors/FactorStereoProjectionPose.h
@@ -26,7 +26,7 @@ struct StereoObservation
 
 /** Smart factor for a set of stereo-camera observations of one point landmark.
  * The ID of the factor is the ID of the landmark.
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_factors_grp
  */
 class FactorStereoProjectionPose : public FactorBase
 {
diff --git a/mola_kernel/include/mola_kernel/factors/SmartFactorIMU.h b/mola_kernel/include/mola_kernel/factors/SmartFactorIMU.h
index a90847da..3a9020e7 100644
--- a/mola_kernel/include/mola_kernel/factors/SmartFactorIMU.h
+++ b/mola_kernel/include/mola_kernel/factors/SmartFactorIMU.h
@@ -20,7 +20,7 @@ namespace mola
 class BackEndBase;
 
 /** Smart factor for a set of IMU measurements (acceleration & gyroscope).
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_factors_grp
  */
 class SmartFactorIMU : public FactorBase
 {
diff --git a/mola_kernel/include/mola_kernel/factors/SmartFactorStereoProjectionPose.h b/mola_kernel/include/mola_kernel/factors/SmartFactorStereoProjectionPose.h
index 1c2cf65c..e72c49a9 100644
--- a/mola_kernel/include/mola_kernel/factors/SmartFactorStereoProjectionPose.h
+++ b/mola_kernel/include/mola_kernel/factors/SmartFactorStereoProjectionPose.h
@@ -23,7 +23,7 @@ class BackEndBase;
 
 /** Smart factor for a set of stereo-camera observations of one point landmark.
  * The ID of the factor is the ID of the landmark.
- * \ingroup mola_kernel_grp
+ * \ingroup mola_kernel_factors_grp
  */
 class SmartFactorStereoProjectionPose : public FactorBase
 {
diff --git a/mola_kernel/include/mola_kernel/interfaces/BackEndBase.h b/mola_kernel/include/mola_kernel/interfaces/BackEndBase.h
index 4af4f632..657ce383 100644
--- a/mola_kernel/include/mola_kernel/interfaces/BackEndBase.h
+++ b/mola_kernel/include/mola_kernel/interfaces/BackEndBase.h
@@ -26,11 +26,15 @@
 
 namespace mola
 {
+/** \addtogroup mola_kernel_interfaces_grp MOLA virtual interfaces
+ *  \ingroup mola_kernel_grp
+ *  @{ */
+
 /** Virtual interface for SLAM back-ends.
  * All calls to `onXXX()` methods are enqueued and executed in a separate
  * thread.
  *
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class BackEndBase : public ExecutableBase
 {
 #if MRPT_VERSION < 0x020e00
@@ -157,4 +161,6 @@ class BackEndBase : public ExecutableBase
         2, mrpt::WorkerThreadsPool::POLICY_FIFO, "slam_backend"};
 };
 
+/** @}  */
+
 }  // namespace mola
diff --git a/mola_kernel/include/mola_kernel/interfaces/Dataset_UI.h b/mola_kernel/include/mola_kernel/interfaces/Dataset_UI.h
index 8b38ef95..aa3f9a5b 100644
--- a/mola_kernel/include/mola_kernel/interfaces/Dataset_UI.h
+++ b/mola_kernel/include/mola_kernel/interfaces/Dataset_UI.h
@@ -16,7 +16,7 @@
 namespace mola
 {
 /** Virtual base for offline dataset sources to have a GUI within MolaViz
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class Dataset_UI
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/ExecutableBase.h b/mola_kernel/include/mola_kernel/interfaces/ExecutableBase.h
index 78c626f5..0b609280 100644
--- a/mola_kernel/include/mola_kernel/interfaces/ExecutableBase.h
+++ b/mola_kernel/include/mola_kernel/interfaces/ExecutableBase.h
@@ -31,7 +31,7 @@ using ProfilerEntry       = mrpt::system::CTimeLoggerEntry;
 using ProfilerSaverAtDtor = mrpt::system::CTimeLoggerSaveAtDtor;
 
 /** Base virtual class for all executable (nodelet-like) units inside a
- * SLAM system. \ingroup mola_kernel_grp */
+ * SLAM system. \ingroup mola_kernel_interfaces_grp */
 class ExecutableBase : public mrpt::system::COutputLogger,  // for logging
                        public mrpt::rtti::CObject,  // RTTI helpers
                        std::enable_shared_from_this<ExecutableBase>
diff --git a/mola_kernel/include/mola_kernel/interfaces/FilterBase.h b/mola_kernel/include/mola_kernel/interfaces/FilterBase.h
index f5262d00..89cd5e8f 100644
--- a/mola_kernel/include/mola_kernel/interfaces/FilterBase.h
+++ b/mola_kernel/include/mola_kernel/interfaces/FilterBase.h
@@ -22,7 +22,7 @@ namespace mola
 /** Base class for filters: get observations via `onNewObservation()`, and
  * immediately send them to a worker thread that works on it, possibly
  * publishing the output via `sendObservationsToFrontEnds()`.
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class FilterBase : public RawDataSourceBase, RawDataConsumer
 {
 #if MRPT_VERSION < 0x020e00
diff --git a/mola_kernel/include/mola_kernel/interfaces/FrontEndBase.h b/mola_kernel/include/mola_kernel/interfaces/FrontEndBase.h
index 85b772b2..92a74116 100644
--- a/mola_kernel/include/mola_kernel/interfaces/FrontEndBase.h
+++ b/mola_kernel/include/mola_kernel/interfaces/FrontEndBase.h
@@ -31,7 +31,7 @@ namespace mola
  * (default=1 Hz), or
  * - Use your own logic to enqueue a task into a worker thread pool (preferred).
  *
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class FrontEndBase : public ExecutableBase, public RawDataConsumer
 {
 #if MRPT_VERSION < 0x020e00
diff --git a/mola_kernel/include/mola_kernel/interfaces/LocalizationSourceBase.h b/mola_kernel/include/mola_kernel/interfaces/LocalizationSourceBase.h
index aacf1085..4c696fa9 100644
--- a/mola_kernel/include/mola_kernel/interfaces/LocalizationSourceBase.h
+++ b/mola_kernel/include/mola_kernel/interfaces/LocalizationSourceBase.h
@@ -31,7 +31,7 @@ namespace mola
  * must call subscribeToLocalizationUpdates() providing a callback that returns
  * as fast as possible.
  *
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class LocalizationSourceBase
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/MapServer.h b/mola_kernel/include/mola_kernel/interfaces/MapServer.h
index f37049bf..a0758dc7 100644
--- a/mola_kernel/include/mola_kernel/interfaces/MapServer.h
+++ b/mola_kernel/include/mola_kernel/interfaces/MapServer.h
@@ -17,7 +17,7 @@
 namespace mola
 {
 /** Virtual interface for map server services offered by MOLA modules
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class MapServer
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/MapSourceBase.h b/mola_kernel/include/mola_kernel/interfaces/MapSourceBase.h
index 688886f7..739d35c0 100644
--- a/mola_kernel/include/mola_kernel/interfaces/MapSourceBase.h
+++ b/mola_kernel/include/mola_kernel/interfaces/MapSourceBase.h
@@ -23,7 +23,7 @@ namespace mola
 {
 /** Virtual interface for SLAM/odometry methods publishing a map
  *
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class MapSourceBase
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/NavStateFilter.h b/mola_kernel/include/mola_kernel/interfaces/NavStateFilter.h
index 0b768974..cb9ea00d 100644
--- a/mola_kernel/include/mola_kernel/interfaces/NavStateFilter.h
+++ b/mola_kernel/include/mola_kernel/interfaces/NavStateFilter.h
@@ -26,7 +26,7 @@ namespace mola
 {
 /** The state returned by NavStateFilter
  *
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 struct NavState
 {
     NavState()  = default;
@@ -52,7 +52,7 @@ struct NavState
 /** Unified API for kinematic state filtering algorithms,
  *  fusing information from multiple odometry or twist sources.
  *
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class NavStateFilter : public mrpt::system::COutputLogger
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/OfflineDatasetSource.h b/mola_kernel/include/mola_kernel/interfaces/OfflineDatasetSource.h
index 1014be96..c509e303 100644
--- a/mola_kernel/include/mola_kernel/interfaces/OfflineDatasetSource.h
+++ b/mola_kernel/include/mola_kernel/interfaces/OfflineDatasetSource.h
@@ -24,7 +24,7 @@ namespace mola
 using trajectory_t = mrpt::poses::CPose3DInterpolator;
 
 /** Virtual base for offline dataset sources
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class OfflineDatasetSource
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/RawDataConsumer.h b/mola_kernel/include/mola_kernel/interfaces/RawDataConsumer.h
index e187cbf8..20cf4d8d 100644
--- a/mola_kernel/include/mola_kernel/interfaces/RawDataConsumer.h
+++ b/mola_kernel/include/mola_kernel/interfaces/RawDataConsumer.h
@@ -20,7 +20,7 @@ namespace mola
 using CObservation = mrpt::obs::CObservation;
 
 /** Virtual base for raw-observation consumers
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class RawDataConsumer
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/RawDataSourceBase.h b/mola_kernel/include/mola_kernel/interfaces/RawDataSourceBase.h
index 04f0996a..1b9be2fb 100644
--- a/mola_kernel/include/mola_kernel/interfaces/RawDataSourceBase.h
+++ b/mola_kernel/include/mola_kernel/interfaces/RawDataSourceBase.h
@@ -27,7 +27,7 @@ namespace mola
 using timestep_t = std::size_t;
 
 /** Virtual base for raw-observation data sources (sensors, dataset
- * parsers,...) \ingroup mola_kernel_grp */
+ * parsers,...) \ingroup mola_kernel_interfaces_grp */
 class RawDataSourceBase : public mola::ExecutableBase
 {
 #if MRPT_VERSION < 0x020e00
diff --git a/mola_kernel/include/mola_kernel/interfaces/Relocalization.h b/mola_kernel/include/mola_kernel/interfaces/Relocalization.h
index 32649adc..970a8ef2 100644
--- a/mola_kernel/include/mola_kernel/interfaces/Relocalization.h
+++ b/mola_kernel/include/mola_kernel/interfaces/Relocalization.h
@@ -17,7 +17,7 @@
 namespace mola
 {
 /** Virtual interface for relocalization offered by MOLA modules
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class Relocalization
 {
    public:
diff --git a/mola_kernel/include/mola_kernel/interfaces/VizInterface.h b/mola_kernel/include/mola_kernel/interfaces/VizInterface.h
index a43e26a7..6f3bda92 100644
--- a/mola_kernel/include/mola_kernel/interfaces/VizInterface.h
+++ b/mola_kernel/include/mola_kernel/interfaces/VizInterface.h
@@ -21,7 +21,7 @@ namespace mola
 {
 /** Virtual visualization interface (see MolaViz)
  *
- * \ingroup mola_kernel_grp */
+ * \ingroup mola_kernel_interfaces_grp */
 class VizInterface
 {
    public: