code: def values_equal(v1, v2):
      if v1 is not None and v2 is not None:
          return round(v1, 3) == round(v2, 3)
      elif v1 is None and v2 is None:
          return True
      return False
  
file_path: pyalgotrade/testcases/technical_stoch_test.py
imports: import datetime
  from six.moves import xrange
  from .None import common
  from pyalgotrade.technical import stoch
  from pyalgotrade.dataseries import bards
  from pyalgotrade import bar
label_desc: Use image node_id 1 for calling a global function with example usage: values_equal(v1, v2) and returns: False, unknown, True