How to use the @istanbuljs/schema.defaults function in @istanbuljs/schema

memokey += memosep + opts.nycrcPath
  }

  /* execFileSync is expensive, avoid it if possible! */
  if (memoize.has(memokey)) {
    return memoize.get(memokey)
  }

  const result = JSON.parse(execFileSync(process.execPath, args))
  const error = result['load-nyc-config-sync-error']
  if (error) {
    throw new Error(error)
  }

  const config = {
    ...schema.defaults.babelPluginIstanbul,
    cwd,
    ...result
  }
  memoize.set(memokey, config)
  return config
}

enter (path) {
          this.__dv__ = null
          this.nycConfig = findConfig(this.opts)
          const realPath = getRealpath(this.file.opts.filename)
          if (shouldSkip(realPath, this.nycConfig)) {
            return
          }
          let { inputSourceMap } = this.opts
          if (this.opts.useInlineSourceMaps !== false) {
            if (!inputSourceMap && this.file.inputMap) {
              inputSourceMap = this.file.inputMap.sourcemap
            }
          }
          const visitorOptions = {}
          Object.entries(schema.defaults.instrumentVisitor).forEach(([name, defaultValue]) => {
            if (name in this.nycConfig) {
              visitorOptions[name] = this.nycConfig[name]
            } else {
              visitorOptions[name] = schema.defaults.instrumentVisitor[name]
            }
          })
          this.__dv__ = programVisitor(t, realPath, {
            ...visitorOptions,
            inputSourceMap
          })
          this.__dv__.enter(path)
        },
        exit (path) {

'use strict';

const { parserPlugins } = require('@istanbuljs/schema').defaults.nyc;

module.exports = {
    cache: false,
    parserPlugins: parserPlugins.concat('typescript')
};

Object.entries(schema.defaults.instrumentVisitor).forEach(([name, defaultValue]) => {
            if (name in this.nycConfig) {
              visitorOptions[name] = this.nycConfig[name]
            } else {
              visitorOptions[name] = schema.defaults.instrumentVisitor[name]
            }
          })
          this.__dv__ = programVisitor(t, realPath, {