parameters: (cls, operators, ys, ys_generate_gradient=False)
return_statement: return ir.GetBackwardPass(ys)
docstring: Gets the backward pass for the list of operators.
  
          Args:
              operators: a list of operators constituting the forward pass.
              ys: a list or a dictionary specifying what blobs we want to compute
                  derivatives of. If the input is a list, we will automatically
                  generate their gradients with all-one values; if the input is a
                  dictionary, for any dictionary entries that are not None, we'll
                  take the corresponding blobs as their gradients; for all those
                  that are None, we will auto-fill them with 1.
          Returns:
              gradient_ops: a list of gradient operators to run.
              all_input_to_grads: a map from input to their corresponding
                  gradients.
docstring_summary: Gets the backward pass for the list of operators.
docstring_tokens: Gets the backward pass for the list of operators .
function: def GetBackwardPass(cls, operators, ys, ys_generate_gradient=False):
          """Gets the backward pass for the list of operators.
  
          Args:
              operators: a list of operators constituting the forward pass.
              ys: a list or a dictionary specifying what blobs we want to compute
                  derivatives of. If the input is a list, we will automatically
                  generate their gradients with all-one values; if the input is a
                  dictionary, for any dictionary entries that are not None, we'll
                  take the corresponding blobs as their gradients; for all those
                  that are None, we will auto-fill them with 1.
          Returns:
              gradient_ops: a list of gradient operators to run.
              all_input_to_grads: a map from input to their corresponding
                  gradients.
          """
          ir = IR(operators)
          return ir.GetBackwardPass(ys)
function_tokens: def GetBackwardPass ( cls , operators , ys , ys_generate_gradient = False ) : ir = IR ( operators ) return ir . GetBackwardPass ( ys )