code: @View(name = "by_issued_date_time", map = "function(doc) { if(doc.token && doc.userId) { emit(doc.issuedDateTime, doc) } }")
      public Collection<CouchDbGoogleAuthenticatorToken> findByIssuedDateTimeBefore(final LocalDateTime localDateTime) {
          val view = createQuery("by_issued_date_time").endKey(localDateTime);
          return db.queryView(view, CouchDbGoogleAuthenticatorToken.class);
      }
docs: Find by issued date.
  
  @param localDateTime time to search for tokens before
  @return tokens issued before given date