<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def numberOfConnectedProximalSynapses(self, cells=None):
 """ Returns the number of proximal connected synapses on these cells. Parameters: @param cells (iterable) Indices of the cells. If None return count for all cells. """

    if cells is None:
      cells = xrange(self.numberOfCells())

    return _countWhereGreaterEqualInRows(self.proximalPermanences, cells,
                                         self.connectedPermanenceProximal)