code: def add_conversion_factor(self, unit, factor):
      def convert(x):
          return x * factor
  
      self.conversions[unit] = convert
  
imports: import math
  from packaging.version import parse
  import numpy
  import matplotlib.ticker
  import matplotlib.units
label_desc: Use image node_id 9 for calling the BasicUnit obj's underlying member method code with example usage: obj.add_conversion_factor(unit, factor) and returns: unknown