parameters: (self, top, propagate_down, bottom)
docstring: This layer does not propagate gradients.
docstring_summary: This layer does not propagate gradients.
docstring_tokens: This layer does not propagate gradients .
function: def backward(self, top, propagate_down, bottom):
          """This layer does not propagate gradients."""
          pass
function_tokens: def backward ( self , top , propagate_down , bottom ) : pass