Missing Parameter while registering class function as subcommand

[unrealintegers]

Summary

subcommand can no longer be registered in classes

Reproduction Steps

See minimal reproducible code below.

Minimal Reproducible Code

from discord import ApplicationContext
from discord.ext import commands


class SampleGroupClass:
    def __init__(self, num: int):
        self.group = bot.create_group("sample", "Sample Description")
        self.num = num

        # call the decorator manually
        self.group.command(name="getnum")(self.sample_callback)

    async def sample_callback(self, ctx: ApplicationContext):
        await ctx.respond(str(self.num))


async def on_ready():
    print("Connected")
    await bot.sync_commands()
    print("Synced")


if __name__ == "__main__":
    bot = commands.Bot()
    sample = SampleGroupClass(3)
    bot.add_listener(on_ready)
    bot.run("")

Expected Results

Prior to commit 6913833c1e076b9c14e7a51ceeb1ff4c156e9164 you could register subcommands inside classes by manually invoking the decorator. However, this update means there is no longer a way to register subcommands inside classes.

Actual Results

Traceback (most recent call last):
  File "/home/unrealintegers/Code/EYES/venv/lib/python3.9/site-packages/discord/commands/core.py", line 668, in _check_required_params
    next(params)
StopIteration

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/unrealintegers/.config/JetBrains/PyCharmCE2021.2/scratches/scratch_4.py", line 25, in <module>
    sample = SampleGroupClass(3)
  File "/home/unrealintegers/.config/JetBrains/PyCharmCE2021.2/scratches/scratch_4.py", line 11, in __init__
    self.group.command(name="getnum")(self.sample_callback)
  File "/home/unrealintegers/Code/EYES/venv/lib/python3.9/site-packages/discord/commands/core.py", line 1041, in wrap
    command = SlashCommand(func, parent=self, **kwargs)
  File "/home/unrealintegers/Code/EYES/venv/lib/python3.9/site-packages/discord/commands/core.py", line 644, in __init__
    self.options: List[Option] = self._parse_options(params)
  File "/home/unrealintegers/Code/EYES/venv/lib/python3.9/site-packages/discord/commands/core.py", line 676, in _parse_options
    params = self._check_required_params(params)
  File "/home/unrealintegers/Code/EYES/venv/lib/python3.9/site-packages/discord/commands/core.py", line 670, in _check_required_params
    raise ClientException(f'Callback for {self.name} command is missing "{p}" parameter.')
discord.errors.ClientException: Callback for getnum command is missing "context" parameter.

Intents

All

System Information

• Python v3.9.7-final
• py-cord v2.0.0-candidate
  • py-cord pkg_resources: v2.0.0rc1
• aiohttp v3.8.1
• system info: Linux 5.17.5-76051705-generic #202204271406165150484021.10~63e51bd SMP PREEMPT Mon May 2 15:

Checklist

• I have searched the open issues for duplicates.
• I have shown the entire traceback, if possible.
• I have removed my token from display, if visible.

Additional Context

The error arises since when a class method is used in its own class, the self parameter is omitted.

[Magma5]

This is already fixed in #1589?