@abc.abstractmethod<EOL><INDENT>def at_end_of_stream(self):<DEDENT>
return<EOL>
Tests if the end of this stream has been reached.

        This may not be a permanent condition as more data may be
        available at a later time as in the case of tailing a file.

        :return: ``true`` if the end of this stream has been reached, ``false`` otherwise
        :rtype: ``boolean``
        :raise: ``IllegalState`` -- this stream has been closed

        *compliance: mandatory -- This method must be implemented.*