<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def getSparsity(self):
 """ Return the sparsity of the current union SDR """

    sparsity = numpy.sum(self._unionSDR) / self._numInputs
    return sparsity