(CommandList
  children: [
    (C {(_Dbg_help_add_sub)} {(set)} {(debug)} 
      {(SQ <"set debug [on|off]\n"> <"\n"> <"When set, we allow debugging the debugger.">)} {(1)}
    )
    (C {(_Dbg_next_complete) (Lit_Other "[") (set)} 
      {(debug) (Lit_Other "]") (Lit_Other "=") (SQ <_Dbg_complete_onoff>)}
    )
    (FuncDef
      name: _Dbg_do_set_debug
      body: 
        (BraceGroup
          children: [
            (C {(_Dbg_set_onoff)} {(DQ ($ VSub_Number "$1"))} {(SQ <debug>)})
            (ControlFlow token:<ControlFlow_Return return> arg_word:{($ VSub_QMark "$?")})
          ]
          spids: [90]
        )
      spids: [86 89]
    )
  ]
)