code: def has_connection(self, i, j):
          
          if (self._conn_represent == conn_represent.MATRIX):
              return (self._osc_conn[i][j]);
          
          elif (self._conn_represent == conn_represent.LIST):
              for neigh_index in range(0, len(self._osc_conn[i]), 1):
                  if (self._osc_conn[i][neigh_index] == j):
                      return True;
              return False;
          
          else:
              raise NameError("Unknown type of representation of coupling");
docs: !
          @brief Returns True if there is connection between i and j oscillators and False - if connection doesn't exist.
          
          @param[in] i (uint): index of an oscillator in the network.
          @param[in] j (uint): index of an oscillator in the network.