@Override
	public boolean isVisible() {
		// Is the CodeViewer visible and the Diff visible?
		return navigatable.isVisible() && diffPlugin.isShowingDiff();
	}
The navigatable for the Diff.
<p>
The CodeViewerService provides Diff with a listing, so where appropriate this navigatable
will defer to the CodeViewerService navigatable.

@param diffPlugin the plugin for the Diff which can be used to obtain needed info.
@param navigatable navigatable that the CodeViewerService provides.
Ghidra/Features/ProgramDiff/src/main/java/ghidra/app/plugin/core/diff/DiffNavigatable.java