(command.CommandList
  children: [
    (C {<set>} {<-e>})
    (C {<git>} {<log>} {<--grep> <Id.Lit_Equals '='> (SQ <'^ARROW-[0-9]*:.*'>)} {<-n1>} 
      {<--pretty> <Id.Lit_Equals '='> <format> <Id.Lit_Colon ':'> <Id.Lit_Other '%'> <H>}
    )
  ]
)