<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_resource_map_members(pid):
 """``pid`` is the PID of a Resource Map or the PID of a member of a Resource Map."""

    if d1_gmn.app.did.is_resource_map_db(pid):
        return get_resource_map_members_by_map(pid)
    elif d1_gmn.app.did.is_resource_map_member(pid):
        return get_resource_map_members_by_member(pid)
    else:
        raise d1_common.types.exceptions.InvalidRequest(
            0, 'Not a Resource Map or Resource Map member. pid="{}"'.format(pid)
        )