presto-raptor-legacy/src/main/java/io/prestosql/plugin/raptor/legacy/metadata/DatabaseMetadataModule.java/DatabaseMetadataModule/createConnectionFactory
class DatabaseMetadataModule:    @ForMetadata
    @Singleton
    @Provides
    public ConnectionFactory createConnectionFactory(@ForMetadata DataSource dataSource)
    {
        return dataSource::getConnection;
    }