@Override
		public void onWorkspaceClosed(@Nonnull Workspace workspace) {
			if (currentWorkspaceGraph != null) {
				currentWorkspaceGraph.onWorkspaceClosed(workspace);
				currentWorkspaceGraph = null;
			}
		}
@return Inheritance graph model for the {@link WorkspaceManager#getCurrent() current workspace}
or {@code null} if no workspace is currently open.
recaf-core/src/main/java/software/coley/recaf/services/inheritance/InheritanceGraphService.java