def pack_element(height, content = nil, &block)
      return if @column_packer.nil?

      if block_given?
        @column_packer.add(height.to_i, capture(&block))
      else
        @column_packer.add(height.to_i, content)
      end
    end
def pack_element(height, content = nil, &block)
      return if @column_packer.nil?

      if block_given?
        @column_packer.add(height.to_i, capture(&block))
      else
        @column_packer.add(height.to_i, content)
      end
    end
Packs a single element with a given height into a column.

 pack_element should be called withing pack_in_columns's block:

   pack_in_columns(3) do
     pack_element(100) do
       "A"
     end
  end

 Accepts parameter strings or block content (ERB, strings, etc).