Fetch all collection by pages of `max` items.
        Parameters
        ----------
        max : int, None (optional)
            The number of item per page. If None, retrieve all collection.

        Returns
        -------
        self    Collection, the fetched collection

def fetch(self, max=None):
        """
        Fetch all collection by pages of `max` items.
        Parameters
        ----------
        max : int, None (optional)
            The number of item per page. If None, retrieve all collection.

        Returns
        -------
        self    Collection, the fetched collection
        """
        if max:
            self.max = max
            n_pages = 0
            while not self._total_pages or n_pages < self._total_pages:
                self.fetch_next_page(True)
                n_pages += 1

            return self
        else:
            return self._fetch()