code: public Process getSubProcessVO(Long id) {
          if (this.getId() != null && this.getId().equals(id)) // Id field is null for instance definitions
              return this;
          if (this.subprocesses == null)
              return null;
          for (Process ret : subprocesses) {
              if (ret.getId().equals(id))
                  return ret;
          }
          return null;
      }
docs: returns the process VO identified by the passed in work id
  It is also possible the sub process is referencing self.
  @param id