code: @Override
      public Map<String, Integer> getGatewayPortMappings() {
  
          final Map<String, Integer> result = new ConcurrentHashMap<String, Integer>();
          final Map<String, String> properties = getValByRegex(GATEWAY_PORT_MAPPING_REGEX);
  
          // Convert port no. from string to int
          for(final Map.Entry<String, String> e : properties.entrySet()) {
              // ignore the GATEWAY_PORT_MAPPING_ENABLED property
              if(!e.getKey().equalsIgnoreCase(GATEWAY_PORT_MAPPING_ENABLED)) {
                  // extract the topology name and use it as a key
                  result.put(StringUtils.substringAfter(e.getKey(), GATEWAY_PORT_MAPPING_PREFIX), Integer.parseInt(e.getValue()) );
              }
  
          }
  
          return Collections.unmodifiableMap(result);
      }
docs: Map of Topology names and their ports.
  
  @return