     }      @Test(expected=NullArgumentException.class)     public void testParametricUsage0() {         final Sigmoid.Parametric g = new Sigmoid.Parametric();         g.gradient(0, null);     }      @Test(expected=DimensionMismatchException.class)     public void testParametricUsage0() {         final Sigmoid.Parametric g = new Sigmoid.Parametric();         g.gradient(0, n