Compare (validate) datastream checksum.  This is a special case of
        :meth:`getDatastream`, with validate checksum set to True. Fedora
        will recalculate the checksum and compare it to the stored value.
        Response is the same content returned by :meth:`getDatastream`,
        with validation result included in the xml.

        :rtype: :class:`requests.models.Response`

def compareDatastreamChecksum(self, pid, dsID, asOfDateTime=None): # date time
        '''Compare (validate) datastream checksum.  This is a special case of
        :meth:`getDatastream`, with validate checksum set to True. Fedora
        will recalculate the checksum and compare it to the stored value.
        Response is the same content returned by :meth:`getDatastream`,
        with validation result included in the xml.

        :rtype: :class:`requests.models.Response`
        '''
        # special case of getDatastream, with validateChecksum = true
        # currently returns datastream info returned by getDatastream...  what should it return?
        return self.getDatastream(pid, dsID, validateChecksum=True, asOfDateTime=asOfDateTime)