code: def get_quantity_scale_factor(self, unit):
      if unit in self._quantity_scale_factors:
          return self._quantity_scale_factors[unit]
      if unit in self._quantity_scale_factors_global:
          mul_factor, other_unit = self._quantity_scale_factors_global[
              unit
          ]
          return mul_factor * self.get_quantity_scale_factor(other_unit)
      return S.One
  
imports: from __future__ import annotations
  import collections
  from functools import reduce
  from sympy.core.basic import Basic
  from sympy.core.containers import Dict, Tuple
  from sympy.core.singleton import S
  from sympy.core.sorting import default_sort_key
  from sympy.core.symbol import Symbol
  from sympy.core.sympify import sympify
  from sympy.matrices.dense import Matrix
  from sympy.functions.elementary.trigonometric import TrigonometricFunction
  from sympy.core.expr import Expr
  from sympy.core.power import Pow
label_desc: Use image node_id 5 for calling the _QuantityMapper obj's underlying member method code with example usage: obj.get_quantity_scale_factor(unit) and returns: S, self, unknown