诺顿定理
https://max.book118.com/html/2017/0620/116780000.shtm


Coding starting point
In irPGMgr::CalcStaticIRDropByZone()  // static IR analysis entrance

	result = SolveStaticIR(false)	// this is default flat IR solve (use PCG solver, which is MT solving)

	else clause  //  this part we need to work on
		    //  Currently, I made partition, solving
		    //   But iteration talk sync is not added yet


As first step, we need to use MT method for partition version of static IR analysis
We need to use LDL solver (rather than PCG MT solver, since MT code can mess up with each other)

How to talk using Norton current source in middle node?
Please check irPGraph::PreCalcTermCurrOnPNode()  as reference


Testing start point
Please study /rnd/jchen/VP_QA_base/QA_utility/test_report_power_network.py

And 

/rnd/jchen/VP_QA_base/QA_suite_v2/ir

These testing cases and utility are preliminary work, please help to enhance script:

If there is difference between IR analysis,
	what is max difference?
	what is average difference?
	what is MSE?
	Figure out error region?