code: def p_NsContentNameAsIdList(p):
      '''
      NsContentNameAsIdList : NsContentNameAsId
                            | NsContentNameAsIdList COMMA NsContentNameAsId
      '''
      if len(p) == 2:
          p[0] = NsContentNameAsIdList(None, p[1])
      else:
          p[0] = NsContentNameAsIdList(p[1], p[3]f p_NsContentNameAsIdList(p):
      '''
      NsContentNameAsIdList : NsContentNameAsId
                            | NsContentNameAsIdList COMMA NsContentNameAsId
      '''
      if len(p) == 2:
          p[0] = NsContentNameAsIdList(None, p[1])
      else:
          p[0] = NsContentNameAsIdList(p[1], p[3])
docs: NsContentNameAsIdList : NsContentNameAsId
                            | NsContentNameAsIdList COMMA NsContentNameAsId