@Override
	public boolean isTransient() {
		return true;
	}
Prompts the user if the editor has unsaved changes. Saves the changes if
the user indicates to do so.
@param allowCancel true if allowed to cancel
@return 0 if the user canceled; 1 if the user saved changes;
2 if the user did not to save changes; 3 if there was an error when
the changes were applied.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/compositeeditor/CompositeEditorProvider.java