(command.CommandList
  children: [
    (command.Simple
      blame_tok: <echo>
      more_env: []
      words: [{<echo>} {(SQ <'--- pgrphack insists on an argument'>)}]
      redirects: []
      do_fork: T
    )
    (command.CommandList
      children: [
        (command.Sentence
          child: 
            (command.Simple
              blame_tok: <pgrphack>
              more_env: []
              words: [{<pgrphack>}]
              redirects: []
              do_fork: T
            )
          terminator: <Id.Op_Semi _>
        )
        (command.Simple
          blame_tok: <echo>
          more_env: []
          words: [{<echo>} {($ Id.VSub_QMark '?')}]
          redirects: []
          do_fork: T
        )
      ]
    )
    (command.Simple
      blame_tok: <echo>
      more_env: []
      words: [{<echo>} {(SQ <'--- pgrphack complains if it cannot run program'>)}]
      redirects: []
      do_fork: T
    )
    (command.CommandList
      children: [
        (command.Sentence
          child: 
            (command.Simple
              blame_tok: <pgrphack>
              more_env: []
              words: [{<pgrphack>} {<'./nonexistent'>}]
              redirects: []
              do_fork: T
            )
          terminator: <Id.Op_Semi _>
        )
        (command.Simple
          blame_tok: <echo>
          more_env: []
          words: [{<echo>} {($ Id.VSub_QMark '?')}]
          redirects: []
          do_fork: T
        )
      ]
    )
    (command.Simple
      blame_tok: <echo>
      more_env: []
      words: [{<echo>} {(SQ <'--- pgrphack runs a program'>)}]
      redirects: []
      do_fork: T
    )
    (command.CommandList
      children: [
        (command.Sentence
          child: 
            (command.Simple
              blame_tok: <pgrphack>
              more_env: []
              words: [{<pgrphack>} {<echo>} {<ok>}]
              redirects: []
              do_fork: T
            )
          terminator: <Id.Op_Semi _>
        )
        (command.Simple
          blame_tok: <echo>
          more_env: []
          words: [{<echo>} {($ Id.VSub_QMark '?')}]
          redirects: []
          do_fork: T
        )
      ]
    )
  ]
)