code: def getCall(self, n): #pylint: disable=invalid-name
          
          call_list = super(SinonSpy, self)._get_wrapper().call_list
          if n >= 0 and n < len(call_list):
              call = call_list[n]
              call.proxy = weakref.proxy(self)
              return call
          else:
              return None
docs: Args:
              n: integer (index of function call)
          Return:
              SpyCall object (or None if the index is not valid)