They needed to replace a valve at work on the main coming into the building. Had to be at least 4". It had a bypass setup to get around the meter and being the curious dude I am I asked the plumber what the plan was (we have a massive ground grid bonded to this setup and were concerned about it) He said they were going to bypass and freeze the pipe to cut out the valve. I thought he was fucking with me but sure as shit that's what they did. Pretty smart whoever figured that out.