code: public boolean addFileSet(FileSet<CopyEntity> fileSet, List<WorkUnit> workUnits) {
      boolean addedWorkunits = addFileSetImpl(fileSet, workUnits);
      if (!addedWorkunits) {
        this.rejectedFileSet = true;
      }
      return addedWorkunits;
    }
docs: Add a file set to the container.
  @param fileSet File set, expressed as a {@link org.apache.gobblin.data.management.partition.FileSet} of {@link CopyEntity}s.
  @param workUnits List of {@link WorkUnit}s corresponding to this file set.
  @return true if the file set was added to the container, false otherwise (i.e. has reached max size).