@classmethod
def fromMessages(cls, messages, instructions=None, labels=None, scripts=
    None, *, id=0):
    """
        Create a BMG from a list of messages.
        """
    self = cls(id=id)
    self.messages = messages
    if instructions is not None:
        self.instructions = instructions
    if labels is not None:
        self.labels = labels
    if scripts is not None:
        self.scripts = scripts
    return self
