objects can be bound to instance variables within an object

oop.rb

(rdb:1) self.margin_box
#<Prawn::Document::BoundingBox:0x10a0a17d8
  @y=756.0,
  @total_left_padding=0,
  @width=356.0, @x=36,
  @stretched_height=nil,
  @document=#<PrawnHelper::JennerPdf:0x10a0a2b10  # <<<< Notice this object DOES NOT end before the comma, #<CLASS::MODULE::OBJECT:ID (no closing >)
    @y=756.0,
    @bounding_box=#<Prawn::Document::BoundingBox:0x10a0a17d8 ...>,  # <<<< Notice this object ends before the comma, #<CLASS::MODULE::OBJECT:ID ...>
    @page_number=1,
    @font_size=12,
    @background=nil,
    @margin_box=#<Prawn::Document::BoundingBox:0x10a0a17d8 ...>,

etc. etc. etc.