sclass Test_CompressToInterpolatedDoubleArray {
  run {
    // just 10 zeros
    var data = new int[10];
    var compressed = CompressToInterpolatedDoubleArray(data)!;
    printStruct(compressed);
    var reconstructed = compressed!;
    var reconstructed2 = iroundDoubleArray(reconstructed);
    assertIntArraysEqual(data, reconstructed2);
    assertEquals(2, compressed.nPillars());
  }
}