C3 problem (bind "this" to nested API) when used with Angular

[mpycio]

• C3 version: 0.6.2
• D3 version: 4.13.0
• Browser: any
• OS: any

I'm getting an error when using this library in Angular project, I'm providing c3js as an injectable service and seem that Angular adds a property called __anonymousType to target function. When binding this to target chart inside `function Chart' on line 1047 this causes an error:

ERROR TypeError: fn[key].bind is not a function
at c3.js:1047
at Array.forEach (<anonymous>)
at bindThis (c3.js:1046)
at c3.js:1049
at Array.forEach (<anonymous>)
at bindThis (c3.js:1046)
at new Chart (c3.js:1052)

Can a simple check be added fn[key].hasOwnProperty('bind') or similar to prevent binding this to any property that other libs may be injecting, this is also future proofing code is some props are not a fn.

[mpycio]

This gets even worse on the following line where this is assigned recursively as this injected prop is a string.. getting a stack overflow. I had to add typeof fn[key] === 'function' check