text: #!/usr/bin/env python2
  # -*- coding: utf-8 -*-
  """
  Created on Fri Mar  3 10:39:32 2017
  
  @author: gtucker
  """
  
  from landlab import RasterModelGrid
  from landlab.components import (DepthDependentDiffuser,
                                  ExponentialWeatherer)
  import numpy as np
  from numpy.testing import assert_array_equal
  from nose.tools import assert_raises
  
  import warnings
  
  def test_raise_kwargs_error():
      mg = RasterModelGrid((5, 5))
      soilTh = mg.add_zeros('node', 'soil__depth')
      z = mg.add_zeros('node', 'topographic__elevation')
      BRz = mg.add_zeros('node', 'bedrock__elevation')
      z += mg.node_x.copy()
      BRz += mg.node_x/2.
      soilTh[:] = z - BRz
      expweath = ExponentialWeatherer(mg)
      assert_raises(TypeError, DepthDependentDiffuser, mg, diffusivity=1)
      
      DDdiff = DepthDependentDiffuser(mg)
      
      assert_raises(TypeError, DDdiff.soilflux, 2., bad_var=1)
  
  