def method_missing(name, *args)
      if @klass.respond_to?(name)
        new_scope = @klass.send(name, *args)
        new_scope.merge(self)
        return new_scope
      else
        return entries.send(name, *args)
      end
    end
def method_missing(name, *args)
      if @klass.respond_to?(name)
        new_scope = @klass.send(name, *args)
        new_scope.merge(self)
        return new_scope
      else
        return entries.send(name, *args)
      end
    end
Used for chaining +Criteria+ scopes together in the for of class methods
 on the +Document+ the criteria is for.

 Options:

 name: The name of the class method on the +Document+ to chain.
 args: The arguments passed to the method.

 Returns: <tt>Criteria</tt>