Try to commit if the Prepare message is ready to be passed into the
        commit phase.

def tryCommit(self, prepare: Prepare):
        """
        Try to commit if the Prepare message is ready to be passed into the
        commit phase.
        """
        rv, reason = self.canCommit(prepare)
        if rv:
            self.doCommit(prepare)
        else:
            self.logger.debug("{} cannot send COMMIT since {}".format(self, reason))