docs: def p_fully_qualified_class_name(p):
      '''fully_qualified_class_name : namespace_name
                                    | NS_SEPARATOR namespace_name
                                    | NAMESPACE NS_SEPARATOR namespace_name'''
      if len(p) == 2:
          p[0] = p[1]
      elif len(p) == 3:
          p[0] = p[1] + p[2]
      else:
          p[0] = p[1] + p[2] + p[3]