code: def parse_version_string(version_string):
      
      components = version_string.split('-') + [None, None]
      version = list(map(int, components[0].split('.')))
      build_tag = components[1] if components[1] else BUILD_TAG
      build_number = int(components[2]) if components[2] else components[2]
  
      return (version, build_tag, build_number)
docs: Parse a version string into it's components.
      
      >>> parse_version_string("0.1")
      ([0, 1], 'jenkins', None)
      >>> parse_version_string("0.3.2-jenkins-3447876")
      ([0, 3, 2], 'jenkins', 3447876)