Use of "ts-jest/presets" within react-native docs

[reggi]

In the react-native docs here I'm a little confused why this imported module is required, named tsjPreset and unused. Is this a mistake or does this do something globally I'm unaware of?

// jest.config.js
const { defaults: tsjPreset } = require('ts-jest/presets')

module.exports = {
  preset: 'react-native',
  globals: {
    'ts-jest': {
      tsconfig: 'tsconfig.spec.json',
    },
  },
  transform: {
    '^.+\\.jsx$': 'babel-jest',
    '^.+\\.tsx?$': 'ts-jest',
  },
  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
}