text: # -*- coding: utf-8 -*-
  from __future__ import division, unicode_literals, print_function, absolute_import
  
  import itertools
  
  from pint.compat import np
  from pint.converters import (ScaleConverter, OffsetConverter, Converter)
  from pint.testsuite import helpers, BaseTestCase
  
  class TestConverter(BaseTestCase):
  
      def test_converter(self):
          c = Converter()
          self.assertTrue(c.is_multiplicative)
          self.assertTrue(c.to_reference(8))
          self.assertTrue(c.from_reference(8))
  
      def test_multiplicative_converter(self):
          c = ScaleConverter(20.)
          self.assertEqual(c.from_reference(c.to_reference(100)), 100)
          self.assertEqual(c.to_reference(c.from_reference(100)), 100)
  
      def test_offset_converter(self):
          c = OffsetConverter(20., 2)
          self.assertEqual(c.from_reference(c.to_reference(100)), 100)
          self.assertEqual(c.to_reference(c.from_reference(100)), 100)
  
      @helpers.requires_numpy()
      def test_converter_inplace(self):
          for c in (ScaleConverter(20.), OffsetConverter(20., 2)):
              fun1 = lambda x, y: c.from_reference(c.to_reference(x, y), y)
              fun2 = lambda x, y: c.to_reference(c.from_reference(x, y), y)
              for fun, (inplace, comp) in itertools.product((fun1, fun2),
                                                            ((True, self.assertIs), (False, self.assertIsNot))):
                  a = np.ones((1, 10))
                  ac = np.ones((1, 10))
                  r = fun(a, inplace)
                  np.testing.assert_allclose(r, ac)
                  comp(a, r)
  