digraph G{
  node [shape=box, label="aaaaaaaaaaaaaa\nddd\l"]
  n [width=3]
  m [width=3, nojustify=true]
  b [nojustify=true]
  n -> m 
  l -> p
  l [shape=record, label="{aaaaaaaaaaaaaa\n | bbbbbb\nddd\l}"]
  p [nojustify=true, shape=record, label="{aaaaaaaaaaaaaa\n | bbbbbb\nddd\l}"]
  a -> b
}