code: def fetch(self, max=None):
          
          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()
docs: 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