setTint(tint) {
    const a = tint.a != null ? tint.a : (this.tint && this.tint.a || 0);
    if (this.tint == null || !cc.colorEqual(this.tint, tint) || (this.tint.a != a)) {
      this.tint = cc.color(tint.r, tint.g, tint.b, a);

      // auto manage tinting component
      this.autoManageComponentById(this.getTinted(), 'Tinting', this.createTintingComponent.bind(this));
    }
  }
Sets the sprite's tint, which changes the color of the sprite towards the tint based on the tint alpha.
NOTE: this uses a horizontal rendering component, which may be performance intensive in some cases.
@param {cc.Color} tint