class_docstr: A directed graph.
  Stores a set of nodes, edges and adjacency matrix.
class_docstr_tok: ["A","directed","graph",".","Stores","a","set","of","nodes",",","edges","and","adjacency","matrix","."]
code: def __init__(self, load_dict={}):
      self.nodes = []
      self.edges = []
      self.adjacency_list = {}
  
      if load_dict and isinstance(load_dict, dict):
          for vertex in load_dict:
              node_from = self.add_node(vertex)
              self.adjacency_list[node_from] = []
              for neighbor in load_dict[vertex]:
                  node_to = self.add_node(neighbor)
                  self.adjacency_list[node_from].append(node_to)
                  self.add_edge(vertex, neighbor)
  
file_path: keon-algos/algorithms/graph/graph.py
label_desc: Use image node_id 1 to create a new DirectedGraph object  with example: obj = DirectedGraph(load_dict)