code: def problem(problem_name, **kwargs):
    
    spec = parse_problem_name(problem_name)
    try:
      return Registries.problems[spec.base_name](
          was_copy=spec.was_copy, was_reversed=spec.was_reversed)
    except KeyError:
      # If name is not found in base problems then try creating an env problem
      return env_problem(problem_name, **kwargs)
docs: Get possibly copied/reversed problem in `base_registry` or `env_registry`.
  
    Args:
      problem_name: string problem name. See `parse_problem_name`.
      **kwargs: forwarded to env problem's initialize method.
  
    Returns:
      possibly reversed/copied version of base problem registered in the given
      registry.