usage of tools PegaAPI
whats the difference between creating objects in below ways
1 java.util.Set PropertiesList = new HashSet();
2 com.pega.pegarules.priv.database.IColPopulation colPop = tools.getColumnPopulationAPI();
why do we require "tools" to create this columnpopulationAPI ?
is it because its a engine API ? if yes, do we need to create tools public API instance to access all Engine APIs ?
Also, how do we get documentation for Engine API ?
Thanks in Advance