code: private Set<String> containerExposedPorts() {
      final Set<String> ports = Sets.newHashSet();
      for (final Map.Entry<String, PortMapping> entry : job.getPorts().entrySet()) {
        final PortMapping mapping = entry.getValue();
        ports.add(containerPort(mapping.getInternalPort(), mapping.getProtocol()));
      }
      return ports;
    }
docs: Create container port exposure configuration for a job.
  
  @return The exposed ports.