class_docstr: Test case of valid data collection interface 
docstr: target: test filter() API for DataCollection 
  method: create an iter data collection and filter it
  expected: return filter successfully
docstr_tok: ["target",":","test","filter","(",")","API","for","DataCollection","method",":","create","an","iter","data","collection","and","filter","it","expected",":","return","filter","successfully"]
code: def test_data_collection_filter_inter(self):
      """
      target: test filter() API for DataCollection
      method: create an iter data collection and filter it
      expected: return filter successfully
      """
      size = 5
      data = iter(range(size))
      dc = towhee.dc(data)
      dc = dc.filter(str)
      result = dc.to_list()
      assert len(result) == size
  
      return True
  
imports: import sys
  import towhee
  import time
  import threading
  import numpy
  import random
  import operator
  from common import common_func
  from towhee import pipe, ops
label_desc: Use image node_id 6 for calling the TestOldDataCollectionAPIsValid obj's underlying member method code with example usage: obj.test_data_collection_filter_inter() and returns: True