code: def test_interval_mul():
      assert (interval(1, 5) * interval(2, 10) == interval(2, 50)) == (
          True,
          True,
      )
      a = interval(-1, 1) * interval(2, 10) == interval(-10, 10)
      assert a == (True, True)
  
      a = interval(-1, 1) * interval(-5, 3) == interval(-5, 5)
      assert a == (True, True)
  
      assert (interval(1, 3) * 2 == interval(2, 6)) == (True, True)
      assert (3 * interval(-1, 2) == interval(-3, 6)) == (True, True)
  
      a = 3 * interval(1, 2, is_valid=False)
      assert a.is_valid is False
  
      a = 3 * interval(1, 2, is_valid=None)
      assert a.is_valid is None
  
      a = interval(1, 5, is_valid=False) * interval(1, 2, is_valid=None)
      assert a.is_valid is False
  
file_path: sympy/sympy/plotting/intervalmath/tests/test_intervalmath.py
imports: from sympy.plotting.intervalmath import interval
  from sympy.testing.pytest import raises
label_desc: Use image node_id 5 for calling a global function with example usage: test_interval_mul() without return types