def get_command(self, name):
        """Get a :class:`.Command` or subclasses from the internal list
        of commands.

        This could also be used as a way to get aliases.

        The name could be fully qualified (e.g. ``'foo bar'``) will get
        the subcommand ``bar`` of the group command ``foo``. If a
        subcommand is not found then ``None`` is returned just as usual.

        Parameters
        -----------
        name: :class:`str`
            The name of the command to get.

        Returns
        --------
        :class:`Command` or subclass
            The command that was requested. If not found, returns ``None``.
        """

        # fast path, no space in name.
        if ' ' not in name:
            return self.all_commands.get(name)

        names = name.split()
        obj = self.all_commands.get(names[0])
        if not isinstance(obj, GroupMixin):
            return obj

        for name in names[1:]:
            try:
                obj = obj.all_commands[name]
            except (AttributeError, KeyError):
                return None

        return obj