async def METHOD_NAME(self, ctx, cmd_name, *, cmd_msg):
    """Set the message to be sent for a given shortcut name."""
    settings: ShortcutSetting = await self.settings_cache.query_one(guild_id=ctx.guild.id)
    if settings is None:
        raise BadArgument("Set a prefix first!")
    if len(cmd_name) > self.MAX_LEN:
        raise BadArgument(f"command names can only be up to {self.MAX_LEN} chars long")
    if not cmd_msg:
        raise BadArgument("can't have null message")
    ent: ShortcutEntry = await self.cache.query_one(guild_id=ctx.guild.id, name=cmd_name)
    if ent:
        ent.value = cmd_msg
    else:
        ent = ShortcutEntry(guild_id=ctx.guild.id, name=cmd_name, value=cmd_msg)
    await ent.update_or_add()
    self.cache.invalidate_entry(guild_id=ctx.guild.id, name=cmd_name)
    await ctx.send("Updated command successfully.")