text: const Task = require('data.task')
  
  // calcSum :: PageRank -> PageRank -> Task PageRank
  // const calcSum = a => b => Task.of(a.rank >= b.rank ? a : b)
  const calcSum = acc => b => Task.of(acc + b.rank)
  
  // calcSum.initialValue = {rank: -Infinity}
  calcSum.initialValue = 0
  
  module.exports = calcSum
  