code: def _generateLocations(self):
      
      size = self.externalInputSize
      bits = self.numInputBits
      random.seed(self.seed)
      self.locations = []
      for _ in xrange(self.numColumns):
        self.locations.append(
          [self._generatePattern(bits, size) for _ in xrange(self.numLocations)]
        )
docs: Generates a pool of locations to be used for the experiments.
  
      For each index, numColumns SDR's are created, as locations for the same
      feature should be different for each column.