code: def get_complete_version(version=None):
      
      if version is None:
          from promise import VERSION
  
          return VERSION
      else:
          assert len(version) == 5
          assert version[3] in ("alpha", "beta", "rc", "final")
  
      return version
docs: Returns a tuple of the promise version. If version argument is non-empty,
      then checks for correctness of the tuple provided.