1. A processor-based method of verifying integrated circuit designs, the method comprising the steps of: constructing with the processor in a processor-accessible memory a series of atomic generators in a staged, hierarchical order, applying with the processor a lowest of the hierarchical generator stages to device level test cases of the verification process, applying with the processor a highest of the hierarchical generator stages to system level test cases of the verification process, reusing processor programming code written for and used in the lowest hierarchical generator stage in a next higher generator stage, creating with the processor a constraint scenario in the highest hierarchical generator stage, and injecting with the processor the constraint scenario into a next lower generator stage.