code: def testPeriod1(self):
      wma = self.__buildWMA([2], [10, 20])
      self.assertTrue(wma[0] == 10)
      self.assertTrue(wma[1] == 20)
  
      self.assertEqual(len(wma.getDateTimes()), 2)
      for i in range(len(wma)):
          self.assertEqual(wma.getDateTimes()[i], None)
  
imports: from six.moves import xrange
  from .None import common
  from pyalgotrade.technical import ma
  from pyalgotrade import dataseries
  from pyalgotrade.barfeed import ninjatraderfeed
  from pyalgotrade import bar
label_desc: Use image node_id 2 for calling the WMATestCase obj's underlying member method code with example usage: obj.testPeriod1() without return types