getExpiration() {
    return this.drmEngine_ ? this.drmEngine_.getExpiration() : Infinity;
  }
Get the next known expiration time for any EME session. If the session
never expires, this will return <code>Infinity</code>. If there are no EME
sessions, this will return <code>Infinity</code>. If the player has not
loaded content, this will return <code>Infinity</code>.

@return {number}
@export