Diagrams drawing bug when using custom Token patterns.

[MrLeebo]

If you try to render the diagram for a parser that contains a custom pattern function, the diagram fails to render.

Repro steps:

1. Visit the playground
2. Change a token to a custom token function, such as var True = createToken({name: "True", pattern: t => null});
3. 💥

Errors during evaluation of the implementation: 
this.children.forEach is not a function

[bd82]

Gracias. 👍

I will look into this.

[bd82]

Will release a version with this fix soon.