(command.CommandList
  children: [
    (C {<set>} {<-e>})
    (C {<echo>} {<warning> <Id.Lit_Colon ':'>} {<this>} {<script>} {<has>} {<been>} {<renamed>} {<to>} 
      {<'./tool/presubmit.sh'>}
    )
    (C 
      {
        (command_sub
          left_token: <Id.Left_DollarParen '$('>
          child: 
            (C {<dirname>} 
              {
                (DQ 
                  (braced_var_sub
                    token: <Id.VSub_Name BASH_SOURCE>
                    bracket_op: (bracket_op.ArrayIndex expr:{<Id.Lit_Digits 0>})
                  )
                )
              }
            )
        ) <'/../tool/presubmit.sh'>
      }
    )
  ]
)