code: function Circle(x, y, radius)
  {
      /**
       * @member {number}
       * @default 0
       */
      this.x = x || 0;
  
      /**
       * @member {number}
       * @default 0
       */
      this.y = y || 0;
  
      /**
       * @member {number}
       * @default 0
       */
      this.radius = radius || 0;
  
      /**
       * The type of the object, mainly used to avoid `instanceof` checks
       *
       * @member {number}
       */
      this.type = CONST.SHAPES.CIRC;
  }
docs: The Circle object can be used to specify a hit area for displayObjects
  
  @class
  @memberof PIXI
  @param x {number} The X coordinate of the center of this circle
  @param y {number} The Y coordinate of the center of this circle
  @param radius {number} The radius of the circle