const turtle = new Turtle();
const turtles = [];
const numTurtles = 10;
for (let j=0; j<numTurtles; j++) {
    turtles[j] = new Turtle();
}
function walk(i) {
    for (let j=0; j<numTurtles; j++) {
        turtles[j].circle(i*(.15+.002*j), 5);
    }
    turtle.forward(i*2)
    turtle.right(180 + i*.03);
    return i < 600;
}