code: public double[] getRangeForBin(int binIndex) {
  		if (binIndex >=0 && binIndex < ranges.length) 
  			return new double[] { ranges[binIndex], ranges[binIndex + 1] };
  		return null;
  	}
docs: Returns the range for the bin at the specified index.
  @param binIndex the index of the bin.
  @return a double array of length 2 where [0] is the lower bound for the
  range and [1] is the upper bound for the range.