digraph sample { 
  graph [rankdir=TD]; node [shape=record];
  op [label="{Operator}"]; 
  op_with_kern [label="{OpWithKernel | InferShape()=0\lRun()\l | map<OpKernelKey,OpKernel>kernels_ }"]
  op_kernel [label="{OpKernel | Compute()=0}"]
  op_kernel_key [label="{OpKernelKey| Place place\n...}"]

  op -> op_with_kern [dir=back, arrowtail=onormal]
  op_with_kern -> op_kernel [arrowhead=vee, label="contains many"]

  {
    rank=same;
    op_with_kern
    op_kernel
  }

  op_kernel -> op_kernel_key [style=invis]

  {
    rank=same;
    op_kernel
    op_kernel_key
  }

  op_with_kern -> op_kernel_key [arrowhead=vee, label ="\nas map key"]
}