Function to create bodies

file.js

createBody(viewportWidth, viewportHeight) {
    let x = this.randomize([0, viewportWidth]);
    let y = this.randomize([0, viewportHeight]);
    let radius = this.randomize(this.options.radiusRange);
    let color = this.options.colors[this.bodies.length % this.options.colors.length];

    return Matter.Bodies.circle(x, y, radius, {
        render: {
            fillStyle: color,
            opacity: this.options.opacity
        },
        frictionAir: this.options.airFriction,
        collisionFilter: {
            group: this.options.collisions ? 1 : -1
        },
        plugin: {
            wrap: {
                min: { x: 0, y: 0 },
                max: { x: viewportWidth, y: viewportHeight }
            }
        }
    });
}