Step 1: Drill Stem Test is a procedure for testing the pressure, permeability and productive capacity of a geological formation during the drilling of a well; 

step 2: To establish whether a well has found a commercial hydrocarbon

similarly, an at-home Covid olfactory test:

Step1: Stick your finger as far as you can up your anus;
Step2: Sniff your finger and if you can't smell your shithole, you're positive.