'Merge two messages, as required for flavor text summarizing'

def merge(self, other):

    assert (self.merge_key == other.merge_key)
    for string in other.strings:
        if (string not in self.strings):
            self.strings.append(string)
    self.colsize = (self.colsize or other.colsize)
    self.pot = (self.pot or other.pot)
    self.source = None
    self.source_crc = None
    self.number_replacement = None
