code: def declared(self, annotationtype, set):
          
          if inspect.isclass(annotationtype): annotationtype = annotationtype.ANNOTATIONTYPE
          return ( (annotationtype,set) in self.annotations) or (set in self.alias_set and self.alias_set[set] and (annotationtype, self.alias_set[set]) in self.annotations )
docs: Checks if the annotation type is present (i.e. declared) in the document.
  
          Arguments:
              annotationtype: The type of annotation, this is conveyed by passing the corresponding annototion class (such as :class:`PosAnnotation` for example), or a member of :class:`AnnotationType`, such as ``AnnotationType.POS``.
              set (str): the set, should formally be a URL pointing to the set definition (aliases are also supported)
  
          Example::
  
              if doc.declared(folia.PosAnnotation, 'http://some/path/brown-tag-set'):
                  ..
  
          Returns:
              bool