code: def update(self, other):
      
      if self._pants_workdir != other._pants_workdir:
        raise ValueError('Other ClasspathProducts from a different pants workdir {}'.format(other._pants_workdir))
      for target, products in other._classpaths._products_by_target.items():
        self._classpaths.add_for_target(target, products)
      for target, products in other._excludes._products_by_target.items():
        self._excludes.add_for_target(target, products)
docs: Adds the contents of other to this ClasspathProducts.