dist/index.js
function JSONPPolling (opts) {
  Polling$2.call(this, opts);

  this.query = this.query || {};

  // define global callbacks array if not present
  // we do this here (lazily) to avoid unneeded global pollution
  if (!callbacks) {
    // we need to consider multiple engines in the same page
    if (!commonjsGlobal.___eio) commonjsGlobal.___eio = [];
    callbacks = commonjsGlobal.___eio;
  }

  // callback identifier
  this.index = callbacks.length;

  // add callback to jsonp global
  var self = this;
  callbacks.push(function (msg) {
    self.onData(msg);
  });

  // append to query string
  this.query.j = this.index;

  // prevent spurious errors from being emitted when the window is unloaded
  if (commonjsGlobal.document && commonjsGlobal.addEventListener) {
    commonjsGlobal.addEventListener('beforeunload', function () {
      if (self.script) self.script.onerror = empty$1;
    }, false);
  }
}
function JSONPPolling (opts) {
  Polling$2.call(this, opts);

  this.query = this.query || {};

  // define global callbacks array if not present
  // we do this here (lazily) to avoid unneeded global pollution
  if (!callbacks) {
    // we need to consider multiple engines in the same page
    if (!commonjsGlobal.___eio) commonjsGlobal.___eio = [];
    callbacks = commonjsGlobal.___eio;
  }

  // callback identifier
  this.index = callbacks.length;

  // add callback to jsonp global
  var self = this;
  callbacks.push(function (msg) {
    self.onData(msg);
  });

  // append to query string
  this.query.j = this.index;

  // prevent spurious errors from being emitted when the window is unloaded
  if (commonjsGlobal.document && commonjsGlobal.addEventListener) {
    commonjsGlobal.addEventListener('beforeunload', function () {
      if (self.script) self.script.onerror = empty$1;
    }, false);
  }
}
JSONP Polling constructor.

@param {Object} opts.
@api public