conflict with other extensions like click-help-colors

[ssbarnea]

Due to the use of custom class, I discovered that I cannot add the default group to a group that is already using it:

from click_help_colors import HelpColorsGroup, HelpColorsCommand

@click.group(
    cls=HelpColorsGroup,
    help_headers_color='yellow'
)

Is there a workaround for this?

[y-marui]

We have to define a new class to combine classes.
eg. DefaultGroup and HelpColorsGroup.