(command.CommandList
  children: [
    (C {<atf_test_case>} {<s_flag>})
    (command.ShFunction
      name: s_flag_head
      body: (command.BraceGroup children:[(C {<atf_set>} {(DQ <descr>)} {(DQ <'Check -s flag'>)})])
    )
    (command.ShFunction
      name: s_flag_body
      body: 
        (command.BraceGroup
          children: [
            (command.Simple
              words: [{<cat>}]
              redirects: [
                (redir.Redir op:<Id.Redir_Great '>'> fd:-1 arg_word:{<input>})
                (redir.HereDoc
                  op: <Id.Redir_DLess '<<'>
                  fd: -1
                  here_begin: {<EOF>}
                  here_end_span_id: 122
                  stdin_parts: [<'a,b,c,d\n'> <'b,c,d\n'> <'c,d\n'> <'d\n'>]
                )
              ]
            )
            (command.Simple
              words: [
                {<atf_check>}
                {<-o>}
                {<inline> <Id.Lit_Other ':'> (SQ <'a\\nb\\nc\\n'>)}
                {<cut>}
                {<-d> <Id.Lit_Comma ','>}
                {<-f>}
                {<1>}
                {<-s>}
              ]
              redirects: [(redir.Redir op:<Id.Redir_Less '<'> fd:-1 arg_word:{<input>})]
            )
            (command.Simple
              words: [
                {<atf_check>}
                {<-o>}
                {<inline> <Id.Lit_Other ':'> (SQ <'d\\n\\n\\n'>)}
                {<cut>}
                {<-d> <Id.Lit_Comma ','>}
                {<-f>}
                {<4>}
                {<-s>}
              ]
              redirects: [(redir.Redir op:<Id.Redir_Less '<'> fd:-1 arg_word:{<input>})]
            )
            (command.Simple
              words: [
                {<atf_check>}
                {<-o>}
                {<inline> <Id.Lit_Other ':'> (SQ <'a,b,\\nb,\\n\\n'>)}
                {<cut>}
                {<-d>}
                {(SQ <c>)}
                {<-f>}
                {<1>}
                {<-s>}
              ]
              redirects: [(redir.Redir op:<Id.Redir_Less '<'> fd:-1 arg_word:{<input>})]
            )
            (command.Simple
              words: [{<atf_check>} {<-o>} {<empty>} {<cut>} {<-d> (SQ <'!'>)} {<-f>} {<1>} {<-s>}]
              redirects: [(redir.Redir op:<Id.Redir_Less '<'> fd:-1 arg_word:{<input>})]
            )
          ]
        )
    )
    (command.ShFunction
      name: atf_init_test_cases
      body: (command.BraceGroup children:[(C {<atf_add_test_case>} {<s_flag>})])
    )
  ]
)