protected boolean isValidAddress(Address addr) {
		if (addr == null || program == null) {
			return false;
		}
		return program.getMemory().contains(addr) || addr.isExternalAddress();
	}
{@link GraphDisplayListener} that handle events back and from program
graphs.
Ghidra/Features/Sarif/src/main/java/sarif/SarifGraphDisplayListener.java