def add_check(self, func, *, call_once=False):
if call_once:<EOL><INDENT>self._check_once.append(func)<EOL><DEDENT>else:<EOL><INDENT>self._checks.append(func)<EOL><DEDENT>
Adds a global check to the bot.

        This is the non-decorator interface to :meth:`.check`
        and :meth:`.check_once`.

        Parameters
        -----------
        func
            The function that was used as a global check.
        call_once: :class:`bool`
            If the function should only be called once per
            :meth:`.Command.invoke` call.