public Set<AbsoluteUnixPath> getVolumes() {
    if (volumes == null) {
      return ImmutableSet.of();
    }
    return volumes.stream().map(AbsoluteUnixPath::get).collect(Collectors.toSet());
  }
Returns a set of {@link AbsoluteUnixPath} representing directories on container to hold volumes
(if specified).

@return set of volumes
jib-cli/src/main/java/com/google/cloud/tools/jib/cli/CommonContainerConfigCliOptions.java