code: function getVelocity(deltaTime, deltaX, deltaY) {
    return new Coordinate(
      finiteOrZero(deltaX / deltaTime),
      finiteOrZero(deltaY / deltaTime),
    );
  }
docs: Calculate the velocity between two points.
  
  @param {number} deltaTime Change in time.
  @param {number} deltaX Change in x.
  @param {number} deltaY Change in y.
  @return {Coordinate} Velocity of the drag.