@throws nullpointerexception if the map or transformer is null
@return a lazy map backed by the given map
@param v <> the value type
@param transformerfactory the factory for creating new objects, must not be null
@param map the map to make lazy, must not be null
@param k <> the key type
file : https_github_com_apache_commons-collections_git/src/main/java/org/apache/commons/collections4/MapUtils.java