Function areAdjacent

areAdjacent(graph, a, b): undefined | true
Returns true if a->b or b->a
Parameters
- graph: Readonly<{
      vertices: IMapImmutable<string, Readonly<{
          id: string;
          out: readonly Readonly<{
              id: string;
              weight?: number;
          }>[];
      }>>;
  }>
- a: Readonly<{
      id: string;
      out: readonly Readonly<{
          id: string;
          weight?: number;
      }>[];
  }>
- b: Readonly<{
      id: string;
      out: readonly Readonly<{
          id: string;
          weight?: number;
      }>[];
  }>
Returns undefined | true