def get_neighbors(graph):
    """Return neighbors/successors for each node in the graph.
    
    Parameters
    ----------
    graph : dgl.DGLGraph
        A DGLGraph for which neighbors will be determined for each
        node

    Returns
    -------
    dict
        a dictionary where nodes' ordinal numbers are keys and lists
        with all the nodes' neighbors are values
    """
    neighbor_dict = {i.item(): [] for i in graph.nodes()}
    for src, dst in zip(graph.edges()[0], graph.edges()[1]):
        neighbor_dict[src.item()].append(dst.item())
    return neighbor_dict