code: def __mul__(self, x):
      return PhysicalQuantity(float(x) * float(self))
  
imports: import pytest
  from numpy import logspace, linspace, geomspace, dtype, array, sctypes, arange, isnan, ndarray, sqrt, nextafter, stack, errstate
  from numpy.testing import assert_, assert_equal, assert_raises, assert_array_equal, assert_allclose
label_desc: Use image node_id 5 for calling the PhysicalQuantity obj's underlying member method code with example usage: obj.__mul__(x) and returns: PhysicalQuantity