Grab only new signals if update is pressed and the shot number matches
Now that I implemented truthyness to my Data class. It should be really easy for me to figure out if I need new signals. I envision traversing the data dictionary like this:
iterate through each subplot location if signal name not there add it to queue to be retrieved from server
Note that if you are looking for data to be retrieved again because the server has updated, you will need to clear the cache first.