(command.CommandList
  children: [
    (command.Simple
      blame_tok: <_Dbg_help_add_sub>
      more_env: []
      words: [
        {<_Dbg_help_add_sub>}
        {<set>}
        {<prompt>}
        {(SQ <'set prompt PROMPT-STRING\n'> <'\n'> <'Set the debugger prompt string.'>)}
        {<1>}
      ]
      redirects: []
      do_fork: T
    )
    (command.ShFunction
      name_tok: <_Dbg_do_set_prompt>
      name: _Dbg_do_set_prompt
      body: 
        (BraceGroup
          left: <Id.Lit_LBrace '{'>
          children: [
            (command.ShAssignment
              left: <Id.Lit_VarLike '_Dbg_prompt_str='>
              pairs: [
                (AssignPair
                  left: <Id.Lit_VarLike '_Dbg_prompt_str='>
                  lhs: 
                    (sh_lhs_expr.Name
                      left: <Id.Lit_VarLike '_Dbg_prompt_str='>
                      name: _Dbg_prompt_str
                    )
                  op: assign_op.Equal
                  rhs: {(DQ ($ Id.VSub_Number 1))}
                )
              ]
              redirects: []
            )
            (command.ControlFlow
              keyword: <Id.ControlFlow_Return return>
              arg_word: {($ Id.VSub_QMark '?')}
            )
          ]
          redirects: []
          right: <Id.Lit_RBrace '}'>
        )
    )
  ]
)