### Question:
SpectralUtils { public static ComplexDoubleMatrix invfft2d(ComplexDoubleMatrix inMatrix) { ComplexDoubleMatrix outMatrix = inMatrix.dup(); invfft2D_inplace(outMatrix); return outMatrix; }  static void fft1D_inplace(ComplexDoubleMatrix vector, final int fftLength); static void invfft1D_inplace(ComplexDoubleMatrix vector, final int fftLength); static ComplexDoubleMatrix fft1D(ComplexDoubleMatrix vector, final int fftLength); static ComplexDoubleMatrix invfft1D(ComplexDoubleMatrix vector, final int fftLength); static ComplexDoubleMatrix fft(ComplexDoubleMatrix inMatrix, final int dimension); static ComplexDoubleMatrix invfft(ComplexDoubleMatrix inMatrix, final int dimension); static void fft_inplace(ComplexDoubleMatrix inMatrix, int dimension); static void invfft_inplace(ComplexDoubleMatrix inMatrix, int dimension); static void fft2D_inplace(ComplexDoubleMatrix A); static ComplexDoubleMatrix fft2D(ComplexDoubleMatrix inMatrix); static void fft2D_inplace(DoubleMatrix A); static void invfft2D_inplace(ComplexDoubleMatrix A); static ComplexDoubleMatrix invfft2d(ComplexDoubleMatrix inMatrix); static ComplexDoubleMatrix fftshift(ComplexDoubleMatrix inMatrix); static DoubleMatrix fftshift(DoubleMatrix inMatrix); static void fftshift_inplace(ComplexDoubleMatrix inMatrix); static void fftshift_inplace(DoubleMatrix inMatrix); static ComplexDoubleMatrix ifftshift(ComplexDoubleMatrix inMatrix); static DoubleMatrix ifftshift(DoubleMatrix inMatrix); static void ifftshift_inplace(ComplexDoubleMatrix inMatrix); static void ifftshift_inplace(DoubleMatrix inMatrix);  }### Answer:
@Test public void testInvfft2D() throws Exception { ComplexDoubleMatrix complexMatrix_ACTUAL = SpectralUtils.invfft2d(fftMatrix_2D_EXPECTED); Assert.assertEquals(complexMatrix_EXPECTED, complexMatrix_ACTUAL); ComplexDoubleMatrix complexMatrix_ACTUAL_2 = SpectralUtils.invfft2d(fftMatrix_2D_EXPECTED_2); Assert.assertEquals(complexMatrix_EXPECTED_2, complexMatrix_ACTUAL_2); }