Test techniques include the process of executing a program or application with the intent of finding software bugs (errors or other defects), and verifying that the software product is fit for use.
You said 'testing software code' it is too general my friend. Kindly site your sources or be more specific what kind of software has been used.
OP is being sarcastic.
SegWit2X was tested for first time and immediately failed:
https://github.com/btc1/bitcoin/issues/65
But the reason SegWit2x failure is someone use ASIC to disrupt the test and mine over 6K blocks less than a day which caused block orphan (because block generation is way too fast). CMIIW.