presto-hive/src/main/java/io/prestosql/plugin/hive/HdfsEnvironment.java/HdfsEnvironment/HdfsContext
class HdfsEnvironment:        public HdfsContext(ConnectorSession session, String schemaName)
        {
            requireNonNull(session, "session is null");
            requireNonNull(schemaName, "schemaName is null");
            this.identity = requireNonNull(session.getIdentity(), "session.getIdentity() is null");
            this.source = requireNonNull(session.getSource(), "session.getSource()");
            this.queryId = Optional.of(session.getQueryId());
            this.schemaName = Optional.of(schemaName);
            this.tableName = Optional.empty();
        }