code: private boolean processAuthenticationResponse(final HttpMethod method) {
  		LOG.trace("enter HttpMethodBase.processAuthenticationResponse("
  			+ "HttpState, HttpConnection)");
  
  		try {
              switch (method.getStatusCode()) {
                  case HttpStatus.SC_UNAUTHORIZED:
                      return processWWWAuthChallenge(method);
                  case HttpStatus.SC_PROXY_AUTHENTICATION_REQUIRED:
                      return processProxyAuthChallenge(method);
                  default:
                      return false;
              }
          } catch (Exception e) {
              if (LOG.isErrorEnabled()) {
                  LOG.error(e.getMessage(), e);
              }
              return false;
          }
  	}
docs: Processes a response that requires authentication
  
  @param method the current {@link HttpMethod HTTP method}
  
  @return <tt>true</tt> if the authentication challenge can be responsed to,
  (that is, at least one of the requested authentication scheme is supported,
  and matching credentials have been found), <tt>false</tt> otherwise.