title: What does `function(*=)` imply in a JSDoc-style code comment?
body: <p>I'm writing some code comments using JSDoc style, and want to know what <code>*=</code> implies in <code>@returns {function(*=): *}</code>, which is generated by WebStorm.</p>
  
  <p>I have tried to search the JSDoc wiki and usejsdoc.org but with no result.</p>
  
  <p>Below is my code:</p>
  
  <pre><code>/**
   * Get record data listener generator.
   * @param {Function} createProps
   * @returns {function(*=): *}        // ** generated by webstorm **
   */
  export function getRecordCustomDataListener(createProps) {
    return (callback) =&gt; onRecordCustomData({ createRecordData: createProps })(callback); // `onRecordCustomData` has not default argument
  }
  </code></pre>
  
  <p>I want to know what <code>*=</code> implies in <code>@returns {function(*=): *}</code>.</p>