docs: def _missingExtraCheck(given, required, extraException, missingException):
      """
      If the L{sets<set>} C{required} and C{given} do not contain the same
      elements raise an exception describing how they are different.
  
      @param given: The L{set} of elements that was actually given.
      @param required: The L{set} of elements that must be given.
  
      @param extraException: An exception to raise if there are elements in
          C{given} that are not in C{required}.
      @param missingException: An exception to raise if there are elements in
          C{required} that are not in C{given}.
  
      @return: C{None}
      """
      extra = given - required
      if extra:
          raise extraException(extra)
  
      missing = required - given
      if missing:
          raise missingException(missing)