code: def FindCheckMacro(line):
    
    for macro in _CHECK_MACROS:
      i = line.find(macro)
      if i >= 0:
        # Find opening parenthesis.  Do a regular expression match here
        # to make sure that we are matching the expected CHECK macro, as
        # opposed to some other macro that happens to contain the CHECK
        # substring.
        matched = Match(r'^(.*\b' + macro + r'\s*)\(', line)
        if not matched:
          continue
        return (macro, len(matched.group(1)))
    return (None, -1)
docs: Find a replaceable CHECK-like macro.
  
    Args:
      line: line to search on.
    Returns:
      (macro name, start position), or (None, -1) if no replaceable
      macro is found.