code: def test_rprop(self):
      nw = algorithms.RPROP(
          self.network,
          minstep=0.001,
          maxstep=1,
          increase_factor=1.1,
          decrease_factor=0.1,
          step=1,
          verbose=False,
      )
  
      nw.train(simple_x_train, simple_y_train, epochs=100)
      self.assertGreater(1e-4, nw.errors.train[-1])
  
file_path: neupy/tests/algorithms/gd/test_rprop.py
imports: import copy
  from functools import partial
  import numpy
  from neupy import algorithms, init, layers
  from neupy.layers import Input, Sigmoid
  from neupy.utils import asfloat
  from helpers import compare_networks
  from base import BaseTestCase
label_desc: Use image node_id 2 for calling the RPROPTestCase obj's underlying member method code with example usage: obj.test_rprop() without return types