def add(self):
        '''Save an object to Instapaper after instantiating it.

        Example::

            folder = Folder(instapaper, title='stuff')
            result = folder.add()
        '''
        # TODO validation per object type
        submit_attribs = {}
        for attrib in self.ATTRIBUTES:
            val = getattr(self, attrib, None)
            if val:
                submit_attribs[attrib] = val
        path = '/'.join([self.RESOURCE, 'add'])
        result = self.client.request(path, submit_attribs)
        return result
Save an object to Instapaper after instantiating it.

        Example::

            folder = Folder(instapaper, title='stuff')
            result = folder.add()