addBulletAnimation(name, frames, frameRate, loop, useNumericIndex) → {Phaser.Weapon}
Adds a new animation under the given key. Optionally set the frames, frame rate and loop.The arguments are all the same as for Animation.add, and work in the same way. Weapon.bulletAnimation will be set to this animation after it's created. From that point on, allbullets fired will play using this animation. You can swap between animations by calling this methodseveral times, and then just changing the Weapon