text: 'use strict'
  class Entity {
      constructor(x, y, dx, dy, width, height, color) {
          this.x = x;
          this.y = y;
          this.dx = dx;
          this.dy = dy;
          this.width = width;
          this.height = height;
          this.color = color;
      }
  
      move(delta) {
          this.x += Math.round(delta * this.dx / 1000);
          this.y += Math.round(delta * this.dy / 1000);
      }
  }
  