code: @Nonnull
      public static List<DockerCloud> getAllDockerClouds() {
          return getInstance().clouds.stream()
                  .filter(Objects::nonNull)
                  .filter(DockerCloud.class::isInstance)
                  .map(cloud -> (DockerCloud) cloud)
                  .collect(Collectors.toList());
      }
docs: Get the list of Docker servers.
  
  @return the list as a LinkedList of DockerCloud