riak solr search 查询results与number不等

riak solr查询时,返回的结果数据{ok, results,number_found}中results数和number_found并不相等,

    Test.get_results 1001,1002,1,60

返回实际数据只有10条,但是number_found=15

{:ok,
 [% pts_i: 63, to_id_i: 1002, unread_i: 0},
  % pts_i: 62, to_id_i: 1002, unread_i: 0},
  % pts_i: 61, to_id_i: 1002, unread_i: 0},
  % pts_i: 60, to_id_i: 1002, unread_i: 0},
  % pts_i: 59, to_id_i: 1002, unread_i: 0},
  % pts_i: 58, to_id_i: 1002, unread_i: 0},
  % pts_i: 57, to_id_i: 1002, unread_i: 0},
  % pts_i: 56, to_id_i: 1002, unread_i: 0},
  % pts_i: 55, to_id_i: 1002, unread_i: 0},
  % pts_i: 54, to_id_i: 1002, unread_i: 0}], 15}

这是riak的bug?