private void initSpacings() {
    for (int i = 0; i < myBlocks.size(); i++) {
      Block block1 = i == 0 ? null : myBlocks.get(i - 1);
      Block block2 = myBlocks.get(i);
      Spacing spacing = calcChildSpacing(i, block1, block2);
      if (spacing != null) {
        registerChildSpacing(block1, block2, spacing);
      }
    }
  }
private void initSpacings()