A function callback.

typedef _Ret_maybenull_ JsValueRef(CALLBACK * JsNativeFunction)(_In_ JsValueRef callee, _In_ bool isConstructCall, _In_ JsValueRef *arguments, _In_ unsigned short argumentCount, _In_opt_ void *callbackState);

• callee: The JavaScript callee.
• isConstructCall: Indicates whether this is a regular call or a 'new' call.
• arguments: The arguments to the call. arguments[0] is this or undefined if the function is called plainly.
• argumentCount: The number of arguments.
• callbackState: The state passed to JsCreateFunction.

The result of the call, if any.