NewtonDefaultUpdateFunction implements NewtonRootFinderMatrixUpdateFunction { @Override public DoubleMatrix2D getUpdatedMatrix(final Function1D<DoubleMatrix1D, DoubleMatrix2D> jacobianFunction, DoubleMatrix1D x, final DoubleMatrix1D deltaX, final DoubleMatrix1D deltaY, final DoubleMatrix2D matrix) { Validate.notNull(jacobianFunction); Validate.notNull(x); return jacobianFunction.evaluate(x); }  @Override DoubleMatrix2D getUpdatedMatrix(final Function1D<DoubleMatrix1D, DoubleMatrix2D> jacobianFunction, DoubleMatrix1D x, final DoubleMatrix1D deltaX, final DoubleMatrix1D deltaY,
      final DoubleMatrix2D matrix);  }
@Test(expectedExceptions = IllegalArgumentException.class) public void testNullFunction() { F.getUpdatedMatrix(null, null, null, null, null); }
@Test(expectedExceptions = IllegalArgumentException.class) public void testNullVector() { F.getUpdatedMatrix(new Function1D<DoubleMatrix1D, DoubleMatrix2D>() { @Override public DoubleMatrix2D evaluate(DoubleMatrix1D x) { return null; } }, null, null, null, null); }