Type hinting / contract hinting

[must]

As an analogy to interfaces in Object Oriented Programming languages, it would provide a basis for best practice coding when there's a kind of type check on each call made out to nodes.

[loreanvictor]

this is a duplicate of #11.

[must]

Just as a little difference to the other issue. I'm talking more type hinting as objects (since most of what's passing is JSON rather than simple types). So it's to be taken into consideration that type hinting as interfaces (again analogy to OOP) could be a powerful way and an extension of the suggestion mentioned in issue #11. Of course this is the be approached carefully as it can add unnecessary clutter and complexity to the platform.