'Generate a signature for a sequence of (key, value) pairs
@param pairs: The pairs to sign, in order
@type pairs: sequence of (str, str)
@return: The binary signature of this sequence of pairs
@rtype: str'

def sign(self, pairs):

    kv = kvform.seqToKV(pairs)
    try:
        mac = self._macs[self.assoc_type]
    except KeyError:
        raise ValueError(('Unknown    association    type:    %r' % (self.assoc_type,)))
    return mac(self.secret, kv)
