removed duplicate docstring

theano/gradient.py

@@ -115,10 +115,6 @@ class DisconnectedType(theano.gof.type.Type):
         because it is disconnected.
     """
 
-    """ A type indicating that the only value a variable can take
-        on is 0. Used primarily to represent that a variable with
-        whose type doesn't support zeros_like has 0 gradient. """
-
     def filter(self, data, strict=False, allow_downcast=None):
         raise AssertionError(
             (