digraph ICache{
    splines=ortho
    compound=true
    node [shape=Mrecord]
	edge [arrowhead=normal]

    IDLE->LOOKUP[xlabel="req" weight=5 color=green]
    LOOKUP->REPLACE[xlabel="~hit" color=blue]
    LOOKUP->IDLE[xlabel="hit" color=red]
    REPLACE->IDLE[xlabel="refilled" color=orange]
}