code: def split(cls, entry):
          
          if enums.SPLITTER in entry:
              return entry.split(enums.SPLITTER, 1)
          else:
              return (entry, None)
docs: Split a declaration name into a (declaration, subpath) tuple.
  
          Examples:
          >>> DeclarationSet.split('foo__bar')
          ('foo', 'bar')
          >>> DeclarationSet.split('foo')
          ('foo', None)
          >>> DeclarationSet.split('foo__bar__baz')
          ('foo', 'bar__baz')