Saving the end product of a sketch

ModestM

I have following code that draws a certain amount of lines. How do I save the end product of the sketch as a picture? If i use save(), it tells me that im mixing up active and static modes. Thanks in advance!

   int x = 10;
    int y = 10;
    int i = 0; 

    void setup() {
      size(640, 480);
      background(50);
    }

    void draw() {
      stroke(#6EBC8D);
      i++;
      if (i<47) {
        line(10, x, 630, y);
      } 
      if (x < height-10) {
        x = x + 10;
      }
      if (x >= height-10) {
        y= y+10;
      }
      stroke(#F01616);
      if (i<47) {
        line(10, x+6, 630, y+6);
      }
      if (x < height-10) {
        x = x + 10;
      }
      if (x >= height-10 ) {
        y= y+10;
      }
    }

GoToLoop

https://Processing.org/reference/saveFrame_.html