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import { reduce } from './reduce.js'
export function collectBy(fn, list){  if (arguments.length === 1){    return _list => collectBy(fn, _list)  }
  const group = reduce(    (o, x) => {      const tag = fn(x)      if (o[ tag ] === undefined){        o[ tag ] = []      }      o[ tag ].push(x)
      return o    },    {},    list  )  const newList = []  for (const tag in group){    newList.push(group[ tag ])  }
  return newList}