void setDiffController(DiffController dc) {
		diffControl = dc;
		execDiffFilter = diffControl.getDiffFilter();
		diffControl.addDiffControllerListener(this);
	}
Used for testing to force file selection dialog instance.
@param dialog project file selection dialog
Ghidra/Features/ProgramDiff/src/main/java/ghidra/app/plugin/core/diff/ProgramDiffPlugin.java