code: def _load(self):
          
          # This will not immediately fetch any sources (entries). It will lazily
          # fetch sources from the server in paginated blocks when this Catalog
          # is iterated over. It will fetch specific sources when they are
          # accessed in this Catalog via __getitem__.
  
          if self.page_size is None:
              # Fetch all source info.
              params = {}
          else:
              # Just fetch the metadata now; fetch source info later in pages.
              params = {'page_offset': 0, 'page_size': 0}
          http_args = self._get_http_args(params)
          response = requests.get(self.info_url, **http_args)
          try:
              response.raise_for_status()
          except requests.HTTPError as err:
              six.raise_from(RemoteCatalogError(
                  "Failed to fetch metadata."), err)
          info = msgpack.unpackb(response.content, **unpack_kwargs)
          self.metadata = info['metadata']
          # The intake server now always provides a length, but the server may be
          # running an older version of intake.
          self._len = info.get('length')
          self._entries.reset()
          # If we are paginating (page_size is not None) and the server we are
          # working with is new enough to support pagination, info['sources']
          # should be empty. If either of those things is not true,
          # info['sources'] will contain all the entries and we should cache them
          # now.
          if info['sources']:
              # Signal that we are not paginating, even if we were asked to.
              self._page_size = None
              self._entries._page_cache.update(
                  {source['name']: RemoteCatalogEntry(
                      url=self.url,
                      getenv=self.getenv,
                      getshell=self.getshell,
                      auth=self.auth,
                      http_args=self.http_args, **source)
                   for source in info['sources']})
docs: Fetch metadata from remote. Entries are fetched lazily.