code: def iter_pulls(self, state=None, head=None, base=None, sort='created',
                     direction='desc', number=-1, etag=None):
          
          url = self._build_url('pulls', base_url=self._api)
          params = {}
          if state and state.lower() in ('all', 'open', 'closed'):
              params['state'] = state.lower()
          params.update(head=head, base=base, sort=sort, direction=direction)
          self._remove_none(params)
          return self._iter(int(number), url, PullRequest, params, etag)
docs: List pull requests on repository.
  
          .. versionchanged:: 0.9.0
  
              - The ``state`` parameter now accepts 'all' in addition to 'open'
                and 'closed'.
  
              - The ``sort`` parameter was added.
  
              - The ``direction`` parameter was added.
  
          :param str state: (optional), accepted values: ('all', 'open',
              'closed')
          :param str head: (optional), filters pulls by head user and branch
              name in the format ``user:ref-name``, e.g., ``seveas:debian``
          :param str base: (optional), filter pulls by base branch name.
              Example: ``develop``.
          :param str sort: (optional), Sort pull requests by ``created``,
              ``updated``, ``popularity``, ``long-running``. Default: 'created'
          :param str direction: (optional), Choose the direction to list pull
              requests. Accepted values: ('desc', 'asc'). Default: 'desc'
          :param int number: (optional), number of pulls to return. Default: -1
              returns all available pull requests
          :param str etag: (optional), ETag from a previous request to the same
              endpoint
          :returns: generator of
              :class:`PullRequest <github3.pulls.PullRequest>`\ s