code: public Set<String> getUpdatedFieldNames() {
          Set<String> fieldNames = new HashSet<String>(m_valueMap.keySet());
          fieldNames.addAll(m_valueRemoveMap.keySet());
          return fieldNames;
      }
docs: Get the names of all fields updated by this object, including fields that have new
  and/or remove values assigned. The set is copied and may be empty but not null.
  
  @return Set of all field names being added or remove for this object.