docs: def parse(log_file):
      """Parse log file."""
      with io.open(os.path.expanduser(log_file), encoding="utf-8") as input_file:
          for line in input_file:
              if "Starting import of XUnit results" in line:
                  obj = XUnitParser
                  break
              elif "Starting import of test cases" in line:
                  obj = TestcasesParser
                  break
              elif "Starting import of requirements" in line:
                  obj = RequirementsParser
                  break
          else:
              raise Dump2PolarionException(
                  "No valid data found in the log file '{}'".format(log_file)
              )
  
          return obj(input_file, log_file).parse()