private String getSelectionRequiredMessage() {
		if (isFilesAndDirectories()) {
			return "Please make a selection";
		}
		else if (isFilesOnly()) {
			return "Please select a file";
		}
		return "Please select a directory";
	}
Returns the selected files.  This will show the file chooser

@return the selected files; an empty array if cancelled or no file was selected
Ghidra/Framework/Docking/src/main/java/docking/widgets/filechooser/GhidraFileChooser.java