text: 'use strict'
  
  const Client = require('./lib/client')
  const Dispatcher = require('./lib/dispatcher')
  const errors = require('./lib/core/errors')
  const Pool = require('./lib/pool')
  const Agent = require('./lib/agent')
  const util = require('./lib/core/util')
  const { InvalidArgumentError } = errors
  const api = require('./lib/api')
  const buildConnector = require('./lib/core/connect')
  const MockClient = require('./lib/mock/mock-client')
  const MockAgent = require('./lib/mock/mock-agent')
  const MockPool = require('./lib/mock/mock-pool')
  const mockErrors = require('./lib/mock/mock-errors')
  
  const nodeVersion = process.versions.node.split('.')
  const nodeMajor = Number(nodeVersion[0])
  const nodeMinor = Number(nodeVersion[1])
  
  Object.assign(Dispatcher.prototype, api)
  
  module.exports.Dispatcher = Dispatcher
  module.exports.Client = Client
  module.exports.Pool = Pool
  module.exports.Agent = Agent
  
  module.exports.buildConnector = buildConnector
  module.exports.errors = errors
  
  let globalDispatcher = new Agent()
  
  function setGlobalDispatcher (agent) {
    if (!agent || typeof agent.dispatch !== 'function') {
      throw new InvalidArgumentError('Argument agent must implement Agent')
    }
    globalDispatcher = agent
  }
  
  function getGlobalDispatcher () {
    return globalDispatcher
  }
  
  function makeDispatcher (fn) {
    return (url, opts, handler) => {
      if (typeof opts === 'function') {
        handler = opts
        opts = null
      }
  
      if (!url || (typeof url !== 'string' && typeof url !== 'object' && !(url instanceof URL))) {
        throw new InvalidArgumentError('invalid url')
      }
  
      if (opts != null && typeof opts !== 'object') {
        throw new InvalidArgumentError('invalid opts')
      }
  
      if (opts && opts.path != null) {
        if (typeof opts.path !== 'string') {
          throw new InvalidArgumentError('invalid opts.path')
        }
  
        url = new URL(opts.path, util.parseOrigin(url))
      } else {
        if (!opts) {
          opts = typeof url === 'object' ? url : {}
        }
  
        url = util.parseURL(url)
      }
  
      const { agent, dispatcher = getGlobalDispatcher() } = opts
  
      if (agent) {
        throw new InvalidArgumentError('unsupported opts.agent. Did you mean opts.client?')
      }
  
      return fn.call(dispatcher, {
        ...opts,
        origin: url.origin,
        path: url.search ? `${url.pathname}${url.search}` : url.pathname,
        method: opts.method || (opts.body ? 'PUT' : 'GET')
      }, handler)
    }
  }
  
  module.exports.setGlobalDispatcher = setGlobalDispatcher
  module.exports.getGlobalDispatcher = getGlobalDispatcher
  
  if (nodeMajor > 16 || (nodeMajor === 16 && nodeMinor >= 5)) {
    const fetchImpl = require('./lib/fetch')
    module.exports.fetch = async function fetch (resource, init) {
      const dispatcher = getGlobalDispatcher()
      return fetchImpl.call(dispatcher, resource, init)
    }
    module.exports.Headers = require('./lib/fetch/headers').Headers
    module.exports.Response = require('./lib/fetch/response').Response
    module.exports.Request = require('./lib/fetch/request').Request
    module.exports.FormData = require('./lib/fetch/formdata').FormData
    module.exports.File = require('./lib/fetch/file').File
  }
  
  module.exports.request = makeDispatcher(api.request)
  module.exports.stream = makeDispatcher(api.stream)
  module.exports.pipeline = makeDispatcher(api.pipeline)
  module.exports.connect = makeDispatcher(api.connect)
  module.exports.upgrade = makeDispatcher(api.upgrade)
  
  module.exports.MockClient = MockClient
  module.exports.MockPool = MockPool
  module.exports.MockAgent = MockAgent
  module.exports.mockErrors = mockErrors
  