code: public Container getMandatoryContainer(String containerIdOrName) throws DockerAccessException {
          Container container = getContainer(containerIdOrName);
          if (container == null) {
              throw new DockerAccessException("Cannot find container %s", containerIdOrName);
          }
          return container;
      }
docs: Get container by id
  
  @param containerIdOrName container id or name
  @return container found
  @throws DockerAccessException if an error occurs or no container with this id or name exists