code: def __create_grid_four_connections(self):
          
          
          side_size = self.__width;
          if (self._conn_represent == conn_represent.MATRIX):
              self._osc_conn = [[0] * self._num_osc for index in range(0, self._num_osc, 1)];
          elif (self._conn_represent == conn_represent.LIST):
              self._osc_conn = [[] for index in range(0, self._num_osc, 1)];
          else:
              raise NameError("Unknown type of representation of connections");
          
          for index in range(0, self._num_osc, 1):
              upper_index = index - side_size;
              lower_index = index + side_size;
              left_index = index - 1;
              right_index = index + 1;
              
              node_row_index = math.ceil(index / side_size);
              if (upper_index >= 0):
                  self.__create_connection(index, upper_index);
              
              if (lower_index < self._num_osc):
                  self.__create_connection(index, lower_index);
              
              if ( (left_index >= 0) and (math.ceil(left_index / side_size) == node_row_index) ):
                  self.__create_connection(index, left_index);
              
              if ( (right_index < self._num_osc) and (math.ceil(right_index / side_size) == node_row_index) ):
                  self.__create_connection(index, right_index);
docs: !
          @brief Creates network with connections that make up four grid structure.
          @details Each oscillator may be connected with four neighbors in line with 'grid' structure: right, upper, left, lower.