    """An abstract response"""

    from time import time

    from MiscUtils import AbstractError

    from Message import Message

    class Response(Message):
        """The abstract response class.

        Response is a type of Message that offers the following:

          * A time stamp (indicating when the response was finished)
          * An output stream

        Response is an abstract class; developers typically use HTTPResponse.

        FUTURE

          * Consider implementing the buffer/flush logic here
            including buffer size.
          * Also, consider then having a method that doesn't allow
            committment until the end.

        """

        ## Init ##

        def __init__(self, trans, strmOut):
            Message.__init__(self)
            self._strmOut = strmOut
            self._transaction = trans

        ## End time ##

        def endTime(self):
            return self._endTime

        def recordEndTime(self):
            """Record the end time of the response.

            Stores the current time as the end time of the response. This should
            be invoked at the end of deliver(). It may also be invoked by the
            application for those responses that never deliver due to an error.

            """
            self._endTime = time()

        ## Output ##

        def write(self, string):
            raise AbstractError(self.__class__)

        def isCommitted(self):
            raise AbstractError(self.__class__)

        def deliver(self):
            raise AbstractError(self.__class__)

        def reset(self):
            raise AbstractError(self.__class__)

        def streamOut(self):
            return self._strmOut

        ## Cleanup ##

        def clearTransaction(self):
            del self._transaction

        ## Exception reporting ##

        _exceptionReportAttrNames = Message._exceptionReportAttrNames + ['endTime']