code: public static Properties loadProperties() {
  
          Properties properties = new Properties();
  
          for (String key : BounceProxyPropertyKeys.getPropertyKeysForSystemProperties()) {
  
              String value = System.getProperty(key);
  
              if (value == null) {
  
                  value = loadPropertyFromFile(key);
  
                  if (value == null) {
                      throw new JoynrRuntimeException("No value for system property '" + key
                              + "' set. Unable to start Bounce Proxy");
                  }
              }
  
              properties.put(key, value);
          }
  
          return properties;
      }
docs: Loads all properties for the bounce proxy that have to be set as system
  properties (see
  {@link BounceProxyPropertyKeys#bounceProxySystemPropertyKeys}) or in the
  file {@value #CONTROLLED_BOUNCE_PROXY_SYSTEM_PROPERTIES}. System
  properties have precedence over the file.
  
  @return
  all properties for the bounce proxy that have to be set as
  system properties
  @throws JoynrRuntimeException
  if not all of the properties were set so that bounce proxy
  won't be able to start up correctly