code: def value(self, unit):
      if unit is None:
          unit = self.unit
      return self._val / unit
  
file_path: matplotlib/galleries/examples/units/evans_test.py
imports: import matplotlib.pyplot
  import numpy
  import matplotlib.ticker
  import matplotlib.units
label_desc: Use image node_id 2 for calling the Foo obj's underlying member method code with example usage: obj.value(unit) and returns: unknown