Your requirements could not be resolved to an installable set of packages. Problem 1 - knplabs/knp-snappy[v1.0, ..., v1.0.2] require symfony/process ~2.3|~3.0 -> found symfony/process[v2.3.0, ..., 2.8.x-dev, v3.0.0-BETA1, ..., 3.4.x-dev] but it conflicts with your root composer.json require (7.0.*). - knplabs/knp-snappy[v1.0.3, ..., v1.0.4] require symfony/process ~2.3 || ~3.0 || ~4.0 -> found symfony/process[v2.3.0, ..., 2.8.x-dev, v3.0.0-BETA1, ..., 3.4.x-dev, v4.0.0-BETA1, ..., 4.4.x-dev] but it conflicts with your root composer.json require (7.0.*). - knplabs/knp-snappy v1.1.0 requires symfony/process ~3.4||~4.1 -> found symfony/process[v3.4.0-BETA1, ..., 3.4.x-dev, v4.1.0-BETA1, ..., 4.4.x-dev] but it conflicts with your root composer.json require (7.0.*). - knplabs/knp-snappy[v1.2.0, ..., v1.3.1] require symfony/process ~3.4||~4.3||~5.0 -> found symfony/process[v3.4.0-BETA1, ..., 3.4.x-dev, v4.3.0-BETA1, ..., 4.4.x-dev, v5.0.0-BETA1, ..., 5.4.x-dev] but it conflicts with your root composer.json require (7.0.*). - knplabs/knp-snappy[v1.4.0, ..., 1.x-dev] require symfony/process ~3.4||~4.3||~5.0||~6.0 -> found symfony/process[v3.4.0-BETA1, ..., 3.4.x-dev, v4.3.0-BETA1, ..., 4.4.x-dev, v5.0.0-BETA1, ..., 5.4.x-dev, v6.0.0-BETA1, ..., 6.4.x-dev] but it conflicts with your root composer.json require (7.0.*). - endroid/pdf 1.5.4 requires knplabs/knp-snappy ^1.0 -> satisfiable by knplabs/knp-snappy[v1.0, ..., 1.x-dev]. - Root composer.json requires endroid/pdf @dev -> satisfiable by endroid/pdf[1.5.4]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.

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