docs: public static List<Block> removeEmptyBlocks(final Collection<Block> blocks) {
        List<Block> cleanBlocks = Lists.newArrayListWithExpectedSize(blocks.size());
        for(Block block : blocks) {
           if(block.content.isEmpty()) {
              continue;
           }
  
           if(isWhitespace(block.content)) {
              continue;
           }
  
           cleanBlocks.add(block);
        }
        return cleanBlocks;
     }