(CommandList
  children: [
    (Assignment
      keyword: Assign_None
      pairs: [
        (assign_pair
          lhs: (LhsName name:test_description)
          op: Equal
          rhs: {(SQ <"histogram diff algorithm">)}
          spids: [4]
        )
      ]
      spids: [4]
    )
    (C {(.)} {(./test-lib.sh)})
    (C {(.)} {(DQ ($ VSub_Name "$TEST_DIRECTORY")) (/lib-diff-alternative.sh)})
    (C {(test_diff_frobnitz)} {(DQ (histogram))})
    (C {(test_diff_unique)} {(DQ (histogram))})
    (C {(test_done)})
  ]
)