code: private void handleAuthenticationType(final Object authenticationType) {
  		if (request != null) {
  			if (authenticationType != null) {
  				// be defensive
  				if (!(authenticationType instanceof String)) {
  					final String message = "Attribute "
  							+ HttpContext.AUTHENTICATION_TYPE
  							+ " expected to be a String but was an ["
  							+ authenticationType.getClass() + "]";
  					LOG.error(message);
  					throw new IllegalArgumentException(message);
  				}
  			}
  			getOsgiAuth().setAuthMethod((String) authenticationType);
  		} else {
  			LOG.warn("Authentication type cannot be set to "
  					+ authenticationType
  					+ ". HttpService specific authentication is disabled because the ServletRequest object cannot be used: "
  					+ "Expected to be an instance of "
  					+ Request.class.getName() + " but got "
  					+ originalRequest.getClass().getName() + ".");
  		}
  	}
docs: Handles setting of authentication type attribute.
  
  @param authenticationType new authentication type