docs: def get_edges(self):
          """
          Returns the edges of the network
  
          Example
          --------
          >>> from pgmpy.readwrite import BIFReader
          >>> reader = BIFReader("bif_test.bif")
          >>> reader.get_edges()
          [['family-out', 'light-on'],
           ['family-out', 'dog-out'],
           ['bowel-problem', 'dog-out'],
           ['dog-out', 'hear-bark']]
          """
          edges = [[value, key] for key in self.variable_parents.keys()
                   for value in self.variable_parents[key]]
          return edges