code: def __missing__(self, key):
      return None
  
imports: from __future__ import division
  from math import copysign
  from collections import OrderedDict
  import numpy
  import logbook
  from catalyst.assets import Future, Asset
  from catalyst.utils.input_validation import expect_types
  from catalyst.constants import LOG_LEVEL
label_desc: Use image node_id 1 for calling the positiondict obj's underlying member method code with example usage: obj.__missing__(key) and returns: None