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