code: def add_node(self, node):
          
          other_nodes = [n for n in self.nodes() if n.id != node.id]
  
          for n in other_nodes:
              if isinstance(n, Source):
                  node.connect(direction="from", whom=n)
              else:
                  node.connect(direction="both", whom=n)
docs: Add a node, connecting it to everyone and back.