def method_missing(method, *args, &block)
      if method[-1] == '='
        # setter
        key = method.slice(0...-1).to_sym

        unless has_key?(key)
          super
        end
        self[key] = args[0]
      else
        unless has_key?(method)
          super
        end

        prop = self[method]
        if prop.is_a? JSFunction
          prop.call_with_instance(self, *args, &block)
        else
          prop
        end
      end
    end
def method_missing(method, *args, &block)
      if method[-1] == '='
        # setter
        key = method.slice(0...-1).to_sym

        unless has_key?(key)
          super
        end
        self[key] = args[0]
      else
        unless has_key?(method)
          super
        end

        prop = self[method]
        if prop.is_a? JSFunction
          prop.call_with_instance(self, *args, &block)
        else
          prop
        end
      end
    end
Gets or sets a JS property, or call it as a method if it is a function.