code: def testMaxLen(self):
      ds = dataseries.SequenceDataSeries()
      for i in xrange(3000):
          ds.append(i)
      self.assertEqual(len(ds), 2048)
      self.assertEqual(ds[0], 952)
      self.assertEqual(ds[-1], 2999)
  
imports: import datetime
  from six.moves import xrange
  from .None import common
  from pyalgotrade import dataseries
  from pyalgotrade.dataseries import bards
  from pyalgotrade.dataseries import aligned
  from pyalgotrade import bar
label_desc: Use image node_id 3 for calling the TestUpdatedDefaultMaxLen obj's underlying member method code with example usage: obj.testMaxLen() without return types