# Buggy code
async def _playlist_update(
    self,
    ctx: commands.Context,
    playlist_matches: PlaylistConverter,
    *,
    scope_data: ScopeParser = None,
):
    """Updates all tracks in a playlist.

    **Usage**:
    ​ ​ ​ ​ [p]playlist update playlist_name_OR_id args

    **Args**:
    ​ ​ ​ ​ The following are all optional:
    ​ ​ ​ ​ ​ ​ ​ ​ --scope <scope>
    ​ ​ ​ ​ ​ ​ ​ ​ --author [user]
    ​ ​ ​ ​ ​ ​ ​ ​ --guild [guild] **Only the bot owner can use this**

    Scope is one of the following:
    ​ ​ ​ ​ Global
    ​ ​ ​ ​ Guild
    ​ ​ ​ ​ User

    Author can be one of the following:
    ​ ​ ​ ​ User ID
    ​ ​ ​ ​ User Mention
    ​ ​ ​ ​ User Name#123

    Guild can be one of the following:
    ​ ​ ​ ​ Guild ID
    ​ ​ ​ ​ Exact guild name

    Example use:
    ​ ​ ​ ​ [p]playlist update MyGuildPlaylist
    ​ ​ ​ ​ [p]playlist update MyGlobalPlaylist --scope Global
    ​ ​ ​ ​ [p]playlist update MyPersonalPlaylist --scope User
    """

    if scope_data is None:
        scope_data = [PlaylistScope.GUILD.value, ctx.author, ctx.guild, False]
    scope, author, guild, specified_user = scope_data
    try:
        playlist_id, playlist_arg = await self._get_correct_playlist_id(
            ctx, playlist_matches, scope, author, guild, specified_user
        )
    except TooManyMatches as e:
        return await self._embed_msg(ctx, str(e))

    if playlist_id is None:
        return await self._embed_msg(
            ctx, _("Could not match '{arg}' to a playlist.").format(arg=playlist_arg)
        )

    if not await self._playlist_check(ctx):
        return
    try:
        playlist = await get_playlist(playlist_id, scope, self.bot, guild, author)
        if not await self.can_manage_playlist(scope, playlist, ctx, author, guild):
            return
        if playlist.url:
            player = lavalink.get_player(ctx.guild.id)
            added, removed, playlist = await self._maybe_update_playlist(
                ctx, player, playlist
            )
        else:
            return await self._embed_msg(ctx, _("Custom playlists cannot be updated."))
    except RuntimeError:
        return await self._embed_msg(
            ctx,
            _("Playlist {id} does not exist in {scope} scope.").format(
                id=playlist_id, scope=humanize_scope(scope, the=True)
            ),
        )
    except MissingGuild:
        return await self._embed_msg(
            ctx, _("You need to specify the Guild ID for the guild to lookup.")
        )
    else:
        scope_name = humanize_scope(
            scope, ctx=guild if scope == PlaylistScope.GUILD.value else author
        )
        if added or removed:
            _colour = await ctx.embed_colour()
            embeds = []
            total_added = len(added)
            total_removed = len(removed)
            total_pages = math.ceil(total_removed / 10) + math.ceil(total_added / 10)
            page_count = 0
            if removed:
                removed_text = ""
                for i, track in enumerate(removed, 1):
                    if len(track.title) > 40:
                        track_title = str(track.title).replace("[", "")
                        track_title = "{}...".format((track_title[:40]).rstrip(" "))
                    else:
                        track_title = track.title
                    removed_text += f"`{i}.` **[{track_title}]({track.uri})**\n"
                    if i % 10 == 0 or i == total_removed:
                        page_count += 1
                        embed = discord.Embed(
                            title=_("Tracks removed"),
                            colour=_colour,
                            description=removed_text,
                        )
                        text = _("Page {page_num}/{total_pages}").format(
                            page_num=page_count, total_pages=total_pages
                        )
                        embed.set_footer(text=text)
                        embeds.append(embed)
                        removed_text = ""
            if added:
                added_text = ""
                for i, track in enumerate(added, 1):
                    if len(track.title) > 40:
                        track_title = str(track.title).replace("[", "")
                        track_title = "{}...".format((track_title[:40]).rstrip(" "))
                    else:
                        track_title = track.title
                    added_text += f"`{i}.` **[{track_title}]({track.uri})**\n"
                    if i % 10 == 0 or i == total_added:
                        page_count += 1
                        embed = discord.Embed(
                            title=_("Tracks added"),
                            colour=_colour,
                            description=added_text,
                        )
                        text = _("Page {page_num}/{total_pages}").format(
                            page_num=page_count, total_pages=total_pages
                        )
                        embed.set_footer(text=text)
                        embeds.append(embed)
                        added_text = ""
            await menu(ctx, embeds, DEFAULT_CONTROLS)
        else:
            return await self._embed_msg(
                ctx,
                _("No changes for {name} (`{id}`) [**{scope}**].").format(
                    id=playlist.id, name=playlist.name, scope=scope_name
                ),
            )


# 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
async def _playlist_update(
    self,
    ctx: commands.Context,
    playlist_matches: PlaylistConverter,
    *,
    scope_data: ScopeParser = None,
):
    """Updates all tracks in a playlist.

    **Usage**:
    ​ ​ ​ ​ [p]playlist update playlist_name_OR_id args

    **Args**:
    ​ ​ ​ ​ The following are all optional:
    ​ ​ ​ ​ ​ ​ ​ ​ --scope <scope>
    ​ ​ ​ ​ ​ ​ ​ ​ --author [user]
    ​ ​ ​ ​ ​ ​ ​ ​ --guild [guild] **Only the bot owner can use this**

    **Scope** is one of the following:
    ​ ​ ​ ​ Global
    ​ ​ ​ ​ Guild
    ​ ​ ​ ​ User

    **Author** can be one of the following:
    ​ ​ ​ ​ User ID
    ​ ​ ​ ​ User Mention
    ​ ​ ​ ​ User Name#123

    **Guild** can be one of the following:
    ​ ​ ​ ​ Guild ID
    ​ ​ ​ ​ Exact guild name

    Example use:
    ​ ​ ​ ​ [p]playlist update MyGuildPlaylist
    ​ ​ ​ ​ [p]playlist update MyGlobalPlaylist --scope Global
    ​ ​ ​ ​ [p]playlist update MyPersonalPlaylist --scope User
    """

    if scope_data is None:
        scope_data = [PlaylistScope.GUILD.value, ctx.author, ctx.guild, False]
    scope, author, guild, specified_user = scope_data
    try:
        playlist_id, playlist_arg = await self._get_correct_playlist_id(
            ctx, playlist_matches, scope, author, guild, specified_user
        )
    except TooManyMatches as e:
        return await self._embed_msg(ctx, title=str(e))

    if playlist_id is None:
        return await self._embed_msg(
            ctx,
            title=_("Playlist Not Found"),
            description=_("Could not match '{arg}' to a playlist.").format(
                arg=playlist_arg
            ),
        )

    if not await self._playlist_check(ctx):
        return
    try:
        playlist = await get_playlist(playlist_id, scope, self.bot, guild, author)
        if not await self.can_manage_playlist(scope, playlist, ctx, author, guild):
            return
        if playlist.url:
            player = lavalink.get_player(ctx.guild.id)
            added, removed, playlist = await self._maybe_update_playlist(
                ctx, player, playlist
            )
        else:
            return await self._embed_msg(
                ctx,
                title=_("Invalid Playlist"),
                description=_("Custom playlists cannot be updated."),
            )
    except RuntimeError:
        return await self._embed_msg(
            ctx,
            title=_("Playlist Not Found"),
            description=_("Playlist {id} does not exist in {scope} scope.").format(
                id=playlist_id, scope=humanize_scope(scope, the=True)
            ),
        )
    except MissingGuild:
        return await self._embed_msg(
            ctx,
            title=_("Missing Arguments"),
            description=_("You need to specify the Guild ID for the guild to lookup."),
        )
    else:
        scope_name = humanize_scope(
            scope, ctx=guild if scope == PlaylistScope.GUILD.value else author
        )
        if added or removed:
            _colour = await ctx.embed_colour()
            removed_embeds = []
            added_embeds = []
            total_added = len(added)
            total_removed = len(removed)
            total_pages = math.ceil(total_removed / 10) + math.ceil(total_added / 10)
            page_count = 0
            if removed:
                removed_text = ""
                for i, track in enumerate(removed, 1):
                    if len(track.title) > 40:
                        track_title = str(track.title).replace("[", "")
                        track_title = "{}...".format((track_title[:40]).rstrip(" "))
                    else:
                        track_title = track.title
                    removed_text += f"`{i}.` **[{track_title}]({track.uri})**\n"
                    if i % 10 == 0 or i == total_removed:
                        page_count += 1
                        embed = discord.Embed(
                            title=_("Tracks removed"),
                            colour=_colour,
                            description=removed_text,
                        )
                        text = _("Page {page_num}/{total_pages}").format(
                            page_num=page_count, total_pages=total_pages
                        )
                        embed.set_footer(text=text)
                        removed_embeds.append(embed)
                        removed_text = ""
            if added:
                added_text = ""
                for i, track in enumerate(added, 1):
                    if len(track.title) > 40:
                        track_title = str(track.title).replace("[", "")
                        track_title = "{}...".format((track_title[:40]).rstrip(" "))
                    else:
                        track_title = track.title
                    added_text += f"`{i}.` **[{track_title}]({track.uri})**\n"
                    if i % 10 == 0 or i == total_added:
                        page_count += 1
                        embed = discord.Embed(
                            title=_("Tracks added"),
                            colour=_colour,
                            description=added_text,
                        )
                        text = _("Page {page_num}/{total_pages}").format(
                            page_num=page_count, total_pages=total_pages
                        )
                        embed.set_footer(text=text)
                        added_embeds.append(embed)
                        added_text = ""
            embeds = removed_embeds + added_embeds
            await menu(ctx, embeds, DEFAULT_CONTROLS)
        else:
            return await self._embed_msg(
                ctx,
                title=_("Playlist Has Not Been Modified"),
                description=_("No changes for {name} (`{id}`) [**{scope}**].").format(
                    id=playlist.id, name=playlist.name, scope=scope_name
                ),
            )