# Buggy code
def standardize_scope(scope) -> str:
    scope = scope.upper()
    valid_scopes = ["GLOBAL", "GUILD", "AUTHOR", "USER", "SERVER", "MEMBER", "BOT"]

    if scope in PlaylistScope.list():
        return scope
    elif scope not in valid_scopes:
        raise InvalidPlaylistScope(
            f'"{scope}" is not a valid playlist scope.'
            f" Scope needs to be one of the following: {humanize_list(valid_scopes)}"
        )

    if scope in ["GLOBAL", "BOT"]:
        scope = PlaylistScope.GLOBAL.value
    elif scope in ["GUILD", "SERVER"]:
        scope = PlaylistScope.GUILD.value
    elif scope in ["USER", "MEMBER", "AUTHOR"]:
        scope = PlaylistScope.USER.value

    return scope


# Traceback (RuntimeError)
Traceback (most recent call last):
File "/home/martinebots/martinebotsvenv/lib/python3.7/site-packages/discord/ext/commands/core.py", line 79, in wrapped
ret = await coro(*args, **kwargs)
File "/home/martinebots/martinebotscogs/cogs_modified/audio/audio.py", line 3183, in play
await self._enqueue_tracks(ctx, query)
File "/home/martinebots/martinebotscogs/cogs_modified/audio/audio.py", line 3885, in _enqueue_tracks
result, called_api = await self.music_cache.lavalink_query(ctx, player, query)
File "/home/martinebots/martinebotscogs/cogs_modified/audio/apis.py", line 911, in lavalink_query
results = await player.load_tracks(query)
File "/home/martinebots/martinebotsvenv/lib/python3.7/site-packages/lavalink/rest_api.py", line 300, in load_tracks
self.__check_node_ready()
File "/home/martinebots/martinebotsvenv/lib/python3.7/site-packages/lavalink/rest_api.py", line 268, in __check_node_ready
raise RuntimeError("Cannot execute REST request when node not ready.")
RuntimeError: Cannot execute REST request when node not ready.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/home/martinebots/martinebotsvenv/lib/python3.7/site-packages/discord/ext/commands/bot.py", line 863, in invoke
await ctx.command.invoke(ctx)
File "/home/martinebots/martinebotsvenv/lib/python3.7/site-packages/discord/ext/commands/core.py", line 728, in invoke
await injected(*ctx.args, **ctx.kwargs)
File "/home/martinebots/martinebotsvenv/lib/python3.7/site-packages/discord/ext/commands/core.py", line 88, in wrapped
raise CommandInvokeError(exc) from exc
discord.ext.commands.errors.CommandInvokeError: Command raised an exception: RuntimeError: Cannot execute REST request when node not ready.```

# Fixed code
def standardize_scope(scope: str) -> str:
    scope = scope.upper()
    valid_scopes = ["GLOBAL", "GUILD", "AUTHOR", "USER", "SERVER", "MEMBER", "BOT"]

    if scope in PlaylistScope.list():
        return scope
    elif scope not in valid_scopes:
        raise InvalidPlaylistScope(
            f'"{scope}" is not a valid playlist scope.'
            f" Scope needs to be one of the following: {humanize_list(valid_scopes)}"
        )

    if scope in ["GLOBAL", "BOT"]:
        scope = PlaylistScope.GLOBAL.value
    elif scope in ["GUILD", "SERVER"]:
        scope = PlaylistScope.GUILD.value
    elif scope in ["USER", "MEMBER", "AUTHOR"]:
        scope = PlaylistScope.USER.value

    return scope