new_contents: from __future__ import division, print_function, absolute_import
  
  from nose.plugins.attrib import attr
  from nose.tools import assert_raises, raises
  
  import numpy as np
  from scipy.stats import norm
  
  from ..npc import (fisher,
                     liptak,
                     tippett)
  
  def test_fisher():
      pvalues = np.linspace(0.05, 0.9, num=5)
      np.testing.assert_almost_equal(fisher(pvalues), 11.11546, 5)
      np.testing.assert_equal(fisher(1), -0.0)
      np.testing.assert_array_less(fisher(10), 0)
      
      
  def test_liptak():
      pvalues = np.linspace(0.05, 0.9, num=5)
      np.testing.assert_almost_equal(liptak(pvalues), 0.5728894, 5)
      np.testing.assert_equal(liptak(1), norm.ppf(0))
      np.testing.assert_equal(liptak(10), np.nan)
      
  
  def test_tippett():
      pvalues = np.linspace(0.05, 0.9, num=5)
      np.testing.assert_almost_equal(tippett(pvalues), 0.95, 5)
      np.testing.assert_equal(tippett(1), 0)
      np.testing.assert_equal(tippett(10), -9)
      
subject: Add tests for combining functions