code: def __call__(self, operation, units):
      if operation not in self.op_dict:
          return NotImplemented
  
      return self.op_dict[operation](self, units)
  
imports: import math
  from packaging.version import parse
  import numpy
  import matplotlib.ticker
  import matplotlib.units
label_desc: Use image node_id 3 for calling the UnitResolver obj's underlying member method code with example usage: obj.__call__(operation, units) and returns: self, NotImplemented