The question is where do you draw the line for checks.  I guess this is OK here, but basically you can only issue this warning if you asked the calc_ccd_temps.py code to give predictions for Obsids X, Y, and Z, but it only returned values for X and Z.  There are many other places in the code where we have a contract with a function that given a certain set of inputs, that it will either fail, or return the correct outputs.