code: def current(self,index=None):
          
          if index is None:
              try:
                  return next(self.select(Current,None,False))
              except StopIteration:
                  raise NoSuchAnnotation
          else:
              for e in self.select(Current,None,False):
                  return e[index]
              raise NoSuchAnnotation
docs: Get the current authoritative annotation (used with suggestions in a structural context)
  
          This returns only one annotation if multiple exist, use `index` to select another in the sequence.
  
          Returns:
              an annotation element (:class:`AbstractElement`)
  
          Raises:
              :class:`NoSuchAnnotation`