}

  /**
   * Returns the transitive closure of {@code graph}. The transitive closure of a graph is another
   * graph with an edge connecting node A to node B if node B is {@link #reachableNodes(Graph,
   * Object) reachable} from node A.
   *
   * <p>This is a "snapshot" based on the current topology of {@code graph}, rather than a live view

/**
 * A class that can supply objects of a single type; a pre-Java-8 version of {@link
 * java.util.function.Supplier java.util.function.Supplier}. Semantically, this could be a factory,
 * generator, builder, closure, or something else entirely. No guarantees are implied by this
 * interface.
 *
 * <p>The {@link Suppliers} class provides common suppliers and related utilities.
 *
 * <p>See the Guava User Guide article on <a href=