How to use the @arrows/multimethod.fromMulti function in @arrows/multimethod

const { multi, method, fromMulti } = require('@arrows/multimethod')

const baseArea = multi(
  (shape) => shape.type,
  method('rectangle', (shape) => shape.a * shape.b),
  method('square', (shape) => shape.a ** 2),
)

/**
 * Creating a new multimethod with many new methods via `fromMulti` function
 */
const area = fromMulti(
  method('circle', (shape) => Math.PI * shape.r ** 2),
  method('triangle', (shape) => 0.5 * shape.a * shape.h),
)(baseArea)

console.log(
  area({ type: 'square', a: 5 }), // -> 25
  area({ type: 'circle', r: 3 }), // -> 28.274333882308138
)

const { multi, method, fromMulti } = require('@arrows/multimethod')

/**
 * Function where the priority does matter
 *
 * @param {number} points
 * @returns {number} grade
 */
const baseGradeExam = multi(
  method((points) => points < 10, 'failed'),
  method((points) => points <= 15, 'ok'),
  method((points) => points > 15, 'good'),
)

const gradeExam = fromMulti(
  method((points) => points === 0, 'terrible'),
  method((points) => points > 20, 'excellent'),
)(baseGradeExam)

console.log(
  gradeExam(0), // -> 'terrible'
  gradeExam(5), // -> 'failed'
  gradeExam(10), // -> 'ok'
  gradeExam(15), // -> 'ok'
  gradeExam(20), // -> 'good'
  gradeExam(25), // -> 'excellent'
)

const data = { name: 'Alice', score: 100 }

save(data, 'json') // -> "Saving as JSON!"
save(data, 'html') // -> "Saving as HTML!"
save(data, 'csv') // -> "Default - saving as TXT!"

const extendedSave = method('csv', (data, format) => {
  console.log('Saving as CSV!')
})(save)

extendedSave(data, 'json') // -> "Saving as JSON!"
extendedSave(data, 'html') // -> "Saving as HTML!"
extendedSave(data, 'csv') // -> "Saving as CSV!"
extendedSave(data, 'yaml') // -> "Default - saving as TXT!"

const extendedSave2 = fromMulti(
  method('csv', (data, format) => {
    console.log('Saving as CSV!')
  }),

  method('yaml', (data, format) => {
    console.log('Saving as YAML!')
  }),
)(save)

extendedSave2(data, 'json') // -> "Saving as JSON!"
extendedSave2(data, 'html') // -> "Saving as HTML!"
extendedSave2(data, 'csv') // -> "Saving as CSV!"
extendedSave2(data, 'yaml') // -> "Saving as YAML!"