Cannot access field volume for writing on Sound.

[plicatibu]

The official example example of Phaser named audio: works perfectly and without any warning / error.

But it's version converted to Haxe generates the error message

Cannot access field or identifier volume for writing

Original Phaser code:

if (pointer.y < 300)
{
        music.volume += 0.1;
}
else
{
        music.volume -= 0.1;
}

Haxe code:

if (pointer.y < 300)
{
    music.volume += 0.1;
}
else
{
    music.volume -= 0.1;
}