public double getTruePositiveRate(int i) {
        Preconditions.checkArgument(i >= 0 && i < tpr.length, "Invalid index: " + i);
        return tpr[i];
    }
public double getTruePositiveRate ( int i ) { Preconditions . checkArgument ( i >= 0 && i < tpr . length , "Invalid index: " + i ) ; return tpr [ i ] ; }
@param i Point number, 0 to numPoints()-1 inclusive
@return True positive rate of a given point