class_docstr: The network morphism search tree.
class_docstr_tok: ["The","network","morphism","search","tree","."]
docstr: add child to search tree itself.
  Arguments:
      u {int} -- father id
      v {int} --  child id
docstr_tok: ["add","child","to","search","tree","itself",".","Arguments",":","u","{","int","}","--","father","id","v","{","int","}","--","child","id"]
code: def add_child(self, u, v):
      """add child to search tree itself.
      Arguments:
          u {int} -- father id
          v {int} --  child id
      """
  
      if u == -1:
          self.root = v
          self.adj_list[v] = []
          return
      if v not in self.adj_list[u]:
          self.adj_list[u].append(v)
      if v not in self.adj_list:
          self.adj_list[v] = []
  
imports: import math
  import random
  from copy import deepcopy
  from functools import total_ordering
  from queue import PriorityQueue
  import numpy
  from scipy.linalg import LinAlgError, cho_solve, cholesky, solve_triangular
  from scipy.optimize import linear_sum_assignment
  from sklearn.metrics.pairwise import rbf_kernel
  from nni.utils import OptimizeMode
  from .graph_transformer import transform
  from .utils import Constant
  from .layers import is_layer
label_desc: Use image node_id 2 for calling the SearchTree obj's underlying member method code with example usage: obj.add_child(u, v) without return types