text: 
  import Vector2D from './Vector2D';
  
  /**
   * A Object that takes an mass of an object and its drag coefficient to calculate
   * the next position of the object.
   *
   * @param  {Integer}   x    The x position of the Vector.
   * @param  {Integer}   y    The y position of the Vector.
   * @param  {Float}     mass The mass of the Euler Object.
   * @param  {Float}     drag The drag caused by the Euler Object.
   * @return {EulerMass}      An object with movement.
   */
  export default function (x, y, mass, drag) {
  
  	return {
  
  		position: new Vector2D(x, y),
  		mass: mass,
  		drag: drag,
  		force: new Vector2D(0, 0),
  		velocity: new Vector2D(0, 0),
  
  		addForce(force) {
  
  			this.force.add(force);
  		},
  
  		integrate(duration) {
  
  			let acc = this.currentForce(this.position);
  			acc.divide(this.mass);
  			let posDelta = new Vector2D(this.velocity.x, this.velocity.y);
  			posDelta.multiply(duration);
  			this.position.add(posDelta);
  			acc.multiply(duration);
  			this.velocity.add(acc);
  			this.force = new Vector2D(0, 0);
  		},
  
  		currentForce(_pos, _vel) {
  
  			let totalForce = new Vector2D(this.force.x, this.force.y);
  			let speed = this.velocity.length();
  			let dragVel = new Vector2D(this.velocity.x, this.velocity.y);
  			dragVel.multiply(this.drag * this.mass * speed);
  			totalForce.subtract(dragVel);
  			return totalForce;
  		}
  	};
  }
  