The main control module is used as a test driver, and the stub are substituted for all modules directly subordinate to the main control module Definitions A source nodein a program is a statement fragment at which program execution begins or resumes first "BEGIN" statement Sources nodes also occur immediately after nodes that transfer control to other units A sink nodein a program is a statement fragment at which program execution terminates final "END" statement statements that transfer control to other units A module execution pathis a sequence of statements that begins with a source node and ends with a sink node, with.
