code: public Map<String, String> getChildrenMap(String parentId) {
  		Map<String, String> map = new HashMap<>();
  		List<StringEntity> children = getByField(Column.PARENT_ID, parentId);
  		for (StringEntity stringEntity : children) {
  			map.put(stringEntity.getId(), stringEntity.getValue());
  		}
  		return map;
  	}
docs: This method returns the map of children associated with given parent id.
  
  @param parentId of parent entity.
  @return map of children