/usr/share/php/Guzzle/Plugin/ is in php-guzzle 3.9.2+dfsg-4.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Guzzle/Plugin/Async/
/usr/share/php/Guzzle/Plugin/Async/AsyncPlugin.php
/usr/share/php/Guzzle/Plugin/Backoff/
/usr/share/php/Guzzle/Plugin/Backoff/AbstractBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/AbstractErrorCodeBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/BackoffLogger.php
/usr/share/php/Guzzle/Plugin/Backoff/BackoffPlugin.php
/usr/share/php/Guzzle/Plugin/Backoff/BackoffStrategyInterface.php
/usr/share/php/Guzzle/Plugin/Backoff/CallbackBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/ConstantBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/CurlBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/ExponentialBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/HttpBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/LinearBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/ReasonPhraseBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Backoff/TruncatedBackoffStrategy.php
/usr/share/php/Guzzle/Plugin/Cache/
/usr/share/php/Guzzle/Plugin/Cache/CacheKeyProviderInterface.php
/usr/share/php/Guzzle/Plugin/Cache/CachePlugin.php
/usr/share/php/Guzzle/Plugin/Cache/CacheStorageInterface.php
/usr/share/php/Guzzle/Plugin/Cache/CallbackCanCacheStrategy.php
/usr/share/php/Guzzle/Plugin/Cache/CanCacheStrategyInterface.php
/usr/share/php/Guzzle/Plugin/Cache/DefaultCacheKeyProvider.php
/usr/share/php/Guzzle/Plugin/Cache/DefaultCacheStorage.php
/usr/share/php/Guzzle/Plugin/Cache/DefaultCanCacheStrategy.php
/usr/share/php/Guzzle/Plugin/Cache/DefaultRevalidation.php
/usr/share/php/Guzzle/Plugin/Cache/DenyRevalidation.php
/usr/share/php/Guzzle/Plugin/Cache/RevalidationInterface.php
/usr/share/php/Guzzle/Plugin/Cache/SkipRevalidation.php
/usr/share/php/Guzzle/Plugin/Cookie/
/usr/share/php/Guzzle/Plugin/Cookie/Cookie.php
/usr/share/php/Guzzle/Plugin/Cookie/CookieJar/
/usr/share/php/Guzzle/Plugin/Cookie/CookieJar/ArrayCookieJar.php
/usr/share/php/Guzzle/Plugin/Cookie/CookieJar/CookieJarInterface.php
/usr/share/php/Guzzle/Plugin/Cookie/CookieJar/FileCookieJar.php
/usr/share/php/Guzzle/Plugin/Cookie/CookiePlugin.php
/usr/share/php/Guzzle/Plugin/Cookie/Exception/
/usr/share/php/Guzzle/Plugin/Cookie/Exception/InvalidCookieException.php
/usr/share/php/Guzzle/Plugin/CurlAuth/
/usr/share/php/Guzzle/Plugin/CurlAuth/CurlAuthPlugin.php
/usr/share/php/Guzzle/Plugin/ErrorResponse/
/usr/share/php/Guzzle/Plugin/ErrorResponse/ErrorResponseExceptionInterface.php
/usr/share/php/Guzzle/Plugin/ErrorResponse/ErrorResponsePlugin.php
/usr/share/php/Guzzle/Plugin/ErrorResponse/Exception/
/usr/share/php/Guzzle/Plugin/ErrorResponse/Exception/ErrorResponseException.php
/usr/share/php/Guzzle/Plugin/History/
/usr/share/php/Guzzle/Plugin/History/HistoryPlugin.php
/usr/share/php/Guzzle/Plugin/Log/
/usr/share/php/Guzzle/Plugin/Log/LogPlugin.php
/usr/share/php/Guzzle/Plugin/Md5/
/usr/share/php/Guzzle/Plugin/Md5/CommandContentMd5Plugin.php
/usr/share/php/Guzzle/Plugin/Md5/Md5ValidatorPlugin.php
/usr/share/php/Guzzle/Plugin/Mock/
/usr/share/php/Guzzle/Plugin/Mock/MockPlugin.php
/usr/share/php/Guzzle/Plugin/Oauth/
/usr/share/php/Guzzle/Plugin/Oauth/OauthPlugin.php