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import {reduceBy} from 'rambda'
test('R.reduceBy', () => {  interface Student {    name: string,    score: number,  }
  const reduceToNamesBy = reduceBy(    (acc: string[], student: Student) => acc.concat(student.name),    []  )  const students = [    {name: 'Lucy', score: 92},    {name: 'Drew', score: 85},    {name: 'Bart', score: 62},  ]  const result = reduceToNamesBy(student => {    const score = student.score    return score < 65      ? 'F'      : score < 70        ? 'D'        : score < 80          ? 'C'          : score < 90            ? 'B'            : 'A'  }, students)  result // $ExpectType { [index: string]: string[]; }})