def __call__(self, **fields):
        """
        Create a new L{eliot.Message} of this type with the given fields.

        @param fields: Extra fields to add to the message.

        @rtype: L{eliot.Message}
        """
        fields[MESSAGE_TYPE_FIELD] = self.message_type
        return Message(fields, self._serializer)
def __call__ ( self , ** fields ) : fields [ MESSAGE_TYPE_FIELD ] = self . message_type return Message ( fields , self . _serializer )
Create a new L{eliot.Message} of this type with the given fields.

        @param fields: Extra fields to add to the message.

        @rtype: L{eliot.Message}