Len Holgate writes: "Once we'd integrated the new data provider we were in a position to do some more testing. We configured the code that used the new component to request the same data from the new component and the old code and to save the data to files. Then we wrote some code to compare the files and highlight any changes. Once that was done we located the source of the differences, wrote tests that failed due to the problems and then started to fix the bugs."