parameters: (grads, op)
docstring: Gets all gradients for op.
docstring_summary: Gets all gradients for op.
docstring_tokens: Gets all gradients for op .
function: def _GetGrads(grads, op):
    """Gets all gradients for op."""
    if op in grads:
      return grads[op]
    else:
      return [[] for _ in xrange(len(op.outputs))]
function_tokens: def _GetGrads ( grads , op ) : if op in grads : return grads [ op ] else : return [ [ ] for _ in xrange ( len ( op . outputs ) ) ]