Use mixed instead of trying to define all types returned.

lib/SimpleSAML/Metadata/MetaDataStorageSource.php

@@ -53,12 +53,7 @@ abstract class SimpleSAML_Metadata_MetaDataStorageSource
      *
      * @param array $sourceConfig Associative array with the configuration for this metadata source.
      *
-     * @return SimpleSAML_Metadata_MetaDataStorageHandlerFlatFile
-     * @return SimpleSAML_Metadata_MetaDataStorageHandlerXML
-     * @return SimpleSAML_Metadata_MetaDataStorageHandlerSerialize
-     * @return SimpleSAML_Metadata_MetaDataStorageHandlerMDX
-     * @return SimpleSAML_Metadata_MetaDataStorageHandlerPdo An instance of a metadata source with the given
-     * configuration.
+     * @return mixed An instance of a metadata source with the given configuration.
      *
      * @throws Exception If the metadata source type is invalid.
      */