text: 
  module.exports = async function(ctx) {
    try {
      let opponents = this.ranktable.getNextBattle();
      let opponent1 = await ctx.call('league.get', {id: opponents[0].id})
      let opponent2 = await ctx.call('league.get', {id: opponents[1].id})
      return [
        opponent1,
        opponent2
      ]
    } catch(error) {
      return null
    }
  }
  