private String getAvailableImplementationClasses() {

    BrowserCapabilitiesRegistry registry = registryInstance.get();

    StringBuilder sb = new StringBuilder();
    for (BrowserCapabilities browser : registry.getAllBrowserCapabilities()) {
      sb.append(browser.getImplementationClassName()).append(", ");
    }
    // trim
    if (sb.lastIndexOf(", ") != -1) {
      sb.delete(sb.length() - 2, sb.length());
    }

    return sb.toString();
  }
  private String getAvailableBrowserCapabilities() {

    BrowserCapabilitiesRegistry registry = registryInstance.get();

    StringBuilder sb = new StringBuilder();
    for (BrowserCapabilities browser : registry.getAllBrowserCapabilities()) {
      if (Validate.nonEmpty(browser.getReadableName())) {
        sb.append(browser.getReadableName()).append(", ");
      }
    }
    // trim
    if (sb.lastIndexOf(", ") != -1) {
      sb.delete(sb.length() - 2, sb.length());
    }

    return sb.toString();
  }