code: def bigger_version(version_string_a, version_string_b):
      
      major_a, minor_a, patch_a = parse_version_string(version_string_a)
      major_b, minor_b, patch_b = parse_version_string(version_string_b)
  
      if major_a > major_b:
          return version_string_a
      elif major_a == major_b and minor_a > minor_b:
          return version_string_a
      elif major_a == major_b and minor_a == minor_b and patch_a > patch_b:
          return version_string_a
      return version_string_b
docs: Returns the bigger version of two version strings.