def v8_context
      V8::C::Locker() do
        context = V8::Context.new
        context.eval(source)
        yield context
      end
    end
def v8_context
      V8::C::Locker() do
        context = V8::Context.new
        context.eval(source)
        yield context
      end
    end
V8 context with Handlerbars code compiled
 @yield [context] V8::Context compiled Handlerbars source code in V8 context