code: def __fill_tree(self, data_list, payload_list):
          
          if data_list is None or len(data_list) == 0:
              return # Just return from here, tree can be filled by insert method later
  
          if payload_list is None:
              # Case when payload is not specified.
              for index in range(0, len(data_list)):
                  self.insert(data_list[index], None)
          else:
              # Case when payload is specified.
              for index in range(0, len(data_list)):
                  self.insert(data_list[index], payload_list[index])
  
          self.__point_comparator = self.__create_point_comparator(type(self.__root.data))
docs: !
          @brief Fill KD-tree by specified data and create point comparator in line with data type.
  
          @param[in] data_list (array_like): Data points that should be inserted to the tree.
          @param[in] payload_list (array_like): Data point payloads that follows data points inserted to the tree.