code: def p_InterfaceDefList(p):
      '''
      InterfaceDefList : InterfaceDef
                       | InterfaceDefList InterfaceDef
      '''
      if len(p) < 3:
          p[0] = InterfaceDefList(None, p[1])
      else:
          p[0] = InterfaceDefList(p[1], p[2]f p_InterfaceDefList(p):
      '''
      InterfaceDefList : InterfaceDef
                       | InterfaceDefList InterfaceDef
      '''
      if len(p) < 3:
          p[0] = InterfaceDefList(None, p[1])
      else:
          p[0] = InterfaceDefList(p[1], p[2])
docs: InterfaceDefList : InterfaceDef
                       | InterfaceDefList InterfaceDef