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export function mapcat(tranformFn, listOfLists){  if (arguments.length === 1){    return _listOfLists => mapcat(tranformFn, _listOfLists)  }
  let willReturn = []  const intermediateResult = listOfLists.map(list =>    list.map(x => tranformFn(x)))
  intermediateResult.forEach(transformedList => {    willReturn = [ ...willReturn, ...transformedList ]  })
  return willReturn}