code: def _testResizeEmptyImpl(self):
      d = self.buildCollection(10)
      self.assertEqual(len(d), 0)
  
      # No resize
      d.resize(10)
  
      # Shrink the array.
      d.resize(5)
      self.assertEqual(len(d), 0)
  
      # Grow the array.
      d.resize(10)
      self.assertEqual(len(d), 0)
  
      # Add one element.
      d.append(20)
      self.assertEqual(len(d), 1)
      self.assertEqual(d[0], 20)
      self.assertEqual(d[-1], 20)
  
imports: import datetime
  from six.moves import xrange
  from .None import common
  from pyalgotrade import utils
  from pyalgotrade.utils import collections
  from pyalgotrade.utils import dt
label_desc: Use image node_id 4 for calling the CollectionTestCaseBase obj's underlying member method code with example usage: obj._testResizeEmptyImpl() without return types