(List
  (Com {[LIT_OTHER ":"]} {[VarSub INTERFACE test_op=VS_TEST_COLON_QMARK {[DQ [LIT_CHARS "Need to set INTERFACE env variable"]]}]})
  (Com {[LIT_OTHER ":"]} {[VarSub CHROME_UNDER_TESTING test_op=VS_TEST_COLON_QMARK {[DQ [LIT_CHARS "Need to set CHROME_UNDER_TESTING env variable"]]}]})
  (If
    (Com {[LIT_OTHER "["]} {[LIT_OTHER "!"]} {[LIT_CHARS -x]} {[DQ [VarSub CHROME_UNDER_TESTING]]} {[LIT_OTHER "]"]})
    (List
      (Com {[LIT_CHARS echo]} {[DQ [LIT_CHARS "CHROME_UNDER_TESTING="][VarSub CHROME_UNDER_TESTING][LIT_CHARS " does not seem to exist."]]})
      (Com {[LIT_CHARS exit]} {[LIT_CHARS 1]})
    )
  )
  (If
    (Com {[LIT_OTHER "["]} {[DQ [VarSub #]]} {[LIT_CHARS -ne]} {[LIT_CHARS 2]} {[LIT_OTHER "]"]})
    (List
      (Com {[LIT_CHARS echo]} {[DQ [LIT_CHARS "Usage: "][VarSub 0][LIT_CHARS " <test-url> <network-dump>"]]})
      (Com {[LIT_CHARS exit]} {[LIT_CHARS 1]})
    )
  )
  (= scope=<EAssignScope.GLOBAL 1> flags=0 words=[] bindings=[('TEST_URL', {[VarSub 1]})])
  (= scope=<EAssignScope.GLOBAL 1> flags=0 words=[] bindings=[('OUTPUT_RECORDING', {[VarSub 2]})])
  (Com {[LIT_CHARS sudo]} {[LIT_CHARS -nv]}
    <
    (FilenameRedirectNode filename={[LIT_CHARS /dev/null]} <REDIR_GREAT ">"> 1),
    (DescriptorRedirectNode target={[LIT_CHARS 1]} <REDIR_GREATAND "2>&"> 2),
    >
  )
  (If
    (Com {[LIT_OTHER "["]} {[VarSub ?]} {[LIT_OTHER "!"] [LIT_OTHER "="]} {[LIT_CHARS 0]} {[LIT_OTHER "]"]})
    (List
      (Com {[LIT_CHARS echo]} {[DQ [LIT_CHARS "Run "][\ LIT_ESCAPED_CHAR "\\\""][LIT_CHARS "sudo -v"][\ LIT_ESCAPED_CHAR "\\\""][LIT_CHARS " to cache your credentials."]]} {[DQ [LIT_CHARS "They are needed to run tcpdump."]]})
      (Com {[LIT_CHARS exit]})
    )
  )
  (Com {[LIT_CHARS echo]} {[DQ [LIT_CHARS "Recording "][VarSub INTERFACE][LIT_CHARS " into "][VarSub OUTPUT_RECORDING]]})
  (Fork
    (Com {[LIT_CHARS sudo]} {[LIT_CHARS -n]} {[LIT_CHARS tcpdump]} {[LIT_CHARS -i]} {[DQ [VarSub INTERFACE]]} {[LIT_CHARS -w]} {[LIT_CHARS -]}
      <
      (FilenameRedirectNode filename={[DQ [VarSub OUTPUT_RECORDING]]} <REDIR_GREAT ">"> 1),
      >
    )
  )
  (= scope=<EAssignScope.GLOBAL 1> flags=0 words=[] bindings=[('TCPDUMP_PID', {[VarSub !]})])
  (Com {[LIT_CHARS echo]} {[DQ [LIT_CHARS "Starting "][VarSub CHROME_UNDER_TESTING][LIT_CHARS " with "][VarSub TEST_URL][LIT_CHARS .]]})
  (Com {[VarSub CHROME_UNDER_TESTING]} {[LIT_CHARS --use-fake-ui-for-media-stream]} {[DQ [VarSub TEST_URL]]})
  (Com {[LIT_CHARS kill]} {[VarSub TCPDUMP_PID]})
)