Collider Process Callback

class Example extends Phaser.Scene
{
    cursors;
    player;

    preload ()
    {
        this.load.setBaseURL('https://cdn.phaserfiles.com/v410');
        this.load.image('sky', 'src/games/firstgame/assets/sky.png');
        this.load.image('ground', 'src/games/firstgame/assets/platform.png');
        this.load.image('star', 'src/games/firstgame/assets/star.png');
        this.load.spritesheet('dude', 'src/games/firstgame/assets/dude.png', {
            frameWidth: 32,
            frameHeight: 48
        });
    }

    create ()
    {
        this.createAnims();

        this.add.image(400, 300, 'sky');

        this.platforms = this.physics.add.staticGroup();

        this.platforms.create(400, 568, 'ground').setScale(2).refreshBody();

        this.platforms.create(400, 400, 'ground').setScale(2, 1).refreshBody();

        this.player = this.physics.add.sprite(100, 450, 'dude');

        this.player.setBounce(0.2);
        this.player.setCollideWorldBounds(true);

        this.cursors = this.input.keyboard.createCursorKeys();

        this.stars = this.physics.add.group({
            allowGravity: false,
            bounceX: 1,
            bounceY: 1,
            collideWorldBounds: true,
            velocityY: -100
        });

        this.stars.createMultiple([
            { key: 'star', quantity: 5, setXY: { x: 200, y: 300, stepX: 100 } },
            { key: 'star', quantity: 5, setXY: { x: 200, y: 500, stepX: 100 } }
        ]);

        this.physics.add.collider(
            this.player,
            this.platforms,
            null,
            (player, platform) =>
            {
                return player.body.velocity.y >= 0;
            });

        this.physics.add.collider(this.stars, this.platforms);

        this.physics.add.overlap(this.player, this.stars, this.collectStar, null, this);
    }

    update ()
    {
        const { left, right, up } = this.cursors;

        if (left.isDown)
        {
            this.player.setVelocityX(-160);

            this.player.anims.play('left', true);
        }
        else if (right.isDown)
        {
            this.player.setVelocityX(160);

            this.player.anims.play('right', true);
        }
        else
        {
            this.player.setVelocityX(0);

            this.player.anims.play('turn');
        }

        if (up.isDown && this.player.body.touching.down)
        {
            this.player.setVelocityY(-330);
        }
    }

    createAnims ()
    {
        this.anims.create({
            key: 'left',
            frames: this.anims.generateFrameNumbers('dude', { start: 0, end: 3 }),
            frameRate: 10,
            repeat: -1
        });

        this.anims.create({
            key: 'turn',
            frames: [ { key: 'dude', frame: 4 } ],
            frameRate: 20
        });

        this.anims.create({
            key: 'right',
            frames: this.anims.generateFrameNumbers('dude', { start: 5, end: 8 }),
            frameRate: 10,
            repeat: -1
        });
    }

    collectStar (player, star)
    {
        star.disableBody(true, true);
    }
}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    parent: 'game-container',
    physics: {
        default: 'arcade',
        arcade: {
            gravity: { y: 300 },
            debug: false
        }
    },
    scene: Example
};

const game = new Phaser.Game(config);