B4J Question How Add Rotate on Java-fPDF library

import java.lang.Math;

public void rotate(double angle, double x = -1, double y = -1) {
    if (x == -1) {
        x = this.x;
    }
    if (y == -1) {
        y = this.y;
    }
    if (this.angle != 0) {
        this._out("Q");
    }
    this.angle = angle;
    if (angle != 0) {
        angle *= Math.PI / 180;
        double c = Math.cos(angle);
        double s = Math.sin(angle);
        double cx = x * this.k;
        double cy = (this.h - y) * this.k;
        this._out(String.format("q %.5f %.5f %.5f %.5f %.2f %.2f cm 1 0 0 1 %.2f %.2f cm", c, s, -s, c, cx, cy, -cx, -cy));
    }
}