void secondProgramOpened() {
		openCloseDiffViewAction.setSelected(true);
		openCloseDiffViewAction.setDescription("Close Diff View");

		Program firstProgram = plugin.getFirstProgram();
		Program secondProgram = plugin.getSecondProgram();
		String firstName = firstProgram.getDomainFile().getName();
		String secondName = secondProgram.getDomainFile().getName();

		//@formatter:off
		openCloseDiffViewAction.setDescription(
			"<html><center>Close Diff View</center><br>" +
			"Current diff: " +
			"<b>"+HTMLUtilities.escapeHTML(firstName)+"</b> to <b>" +HTMLUtilities.escapeHTML(secondName)+"</b>");
		//@formatter:on
	}
Notification to the action manager that a program was opened as the
second program to the program Diff. Actions are adjusted accordingly.
Ghidra/Features/ProgramDiff/src/main/java/ghidra/app/plugin/core/diff/DiffActionManager.java