'Construct a Message containing a set of POST arguments.'

def fromPostArgs(cls, args):

    self = cls()
    openid_args = {}
    for (key, value) in args.items():
        if isinstance(value, list):
            raise TypeError(('query    dict    must    have    one    value    for    each    key,    not    lists    of    values.        Query    is    %r' % (args,)))
        try:
            (prefix, rest) = key.split('.', 1)
        except ValueError:
            prefix = None
        if (prefix != 'openid'):
            self.args[(BARE_NS, key)] = value
        else:
            openid_args[rest] = value
    self._fromOpenIDArgs(openid_args)
    return self
