new_contents: # coding: utf8
  from __future__ import unicode_literals
  
  import numpy
  
  from ...linear.linear import LinearModel
  
  
  def test_init():
      model = LinearModel(3)
      keys = numpy.ones((5,), dtype="uint64")
      values = numpy.ones((5,), dtype="f")
      lengths = numpy.zeros((2,), dtype="long")
      lengths[0] = 3
      lengths[1] = 2
      scores, backprop = model.begin_update((keys, values, lengths))
      assert scores.shape == (2, 3)
      d_feats = backprop(scores)
      assert d_feats is None
  
subject: Add basic test for LinearModel