comefrom: <qiyuangong>102_Binary_Tree_Level_Order_Traversal_1.py
code: def levelOrder( root):
      if root is None:
          return []
      q = [[root]]
      for level in q:
          record = []
          for node in level:
              if node.left:
                  record.append(node.left)
              if node.right:
                  record.append(node.right)
          if record:
              q.append(record)
      return [[x.val for x in level] for level in q]
masked: def sample_funcname ( var_0 ) :
      if var_0 is None :
          return [ ]
      var_2 = [ [ var_0 ] ]
      for var_3 in var_2 :
          var_4 = [ ]
          for var_5 in var_3 :
              if var_5.left :
                  var_4.append ( var_5.left )
              if var_5.right :
                  var_4.append ( var_5.right )
          if var_4 :
              var_2.append ( var_4 )
      return [ [ var_9.val for var_9 in var_3 ] for var_3 in var_2 ]
  