code: private ListBLock createChildListBlock(boolean numbered, Block parentBlock)
      {
          ListBLock childListBlock =
              numbered ? new NumberedListBlock(Collections.emptyList()) : new BulletedListBlock(Collections.emptyList());
  
          if (parentBlock != null) {
              parentBlock.addChild(childListBlock);
          }
  
          return childListBlock;
      }
docs: Create a new ListBlock and add it in the provided parent block.
  
  @param numbered indicate if the list has to be numbered or with bullets
  @param parentBlock the block where to add the new list block.
  @return the new list block.