The builder pattern

The builder pattern is used to instantiate an object of a complex class using the step-by-step approach and return a constructed object at once.

The intention of the factory method and abstract factory method patterns is to use polymorphism to construct objects, as discussed in the initial part of this book. However, in this design pattern, a new independent Builder class is used to construct objects. This pattern is very useful when many parameters are needed to construct and initialize an object.

Developers of Universal Call Center were enjoying their success after the implementation of the singleton pattern and resolving excess SOQL queries. Now, it was time to write a test class for the code written in the singleton design pattern.

Developers came up with the following test class:

@isTest(SeeAllData = false) 
public class OpportunityTriggerTest { 
     
    //Test method to test if state is populated 
    //on Opportunity and Brokers 
    static...