public static class FlowGraph.EdgeKey
This class provides an identifying label for edges in the flow graph.
Thus, the condition of an if statement will have at least two edges
leaving it (in a forward flow graph): one will have the EdgeKey
FlowGraph.EDGE_KEY_TRUE, and is the flow that is taken when the condition
evaluates to true, and one will have the EdgeKey FlowGraph.EDGE_KEY_FALSE,
and is the flow that is taken when the condition evaluates to false.
The differentiation of the flow graph edges allows for a finer grain
data flow analysis, as the dataflow equations can incorporate the
knowledge that a condition is true or false on certain flow paths.