docs: def open(self, uri, **kwargs):
  		""" Return handler instance that matches the specified URI. WSchemeCollection.NoHandlerFound and
  		WSchemeCollection.SchemeIncompatible may be raised.
  
  		:param uri: URI to search handler for
  		:param kwargs: additional arguments that may be used by a handler specialization
  		:return: WSchemeHandler
  		"""
  		handler = self.handler(uri.scheme())
  		if handler is None:
  			raise WSchemeCollection.NoHandlerFound(uri)
  
  		if uri.scheme() is None:
  			uri.component('scheme', handler.scheme_specification().scheme_name())
  
  		if handler.scheme_specification().is_compatible(uri) is False:
  			raise WSchemeCollection.SchemeIncompatible(uri)
  
  		return handler.create_handler(uri, **kwargs)