Sometimes running days data is provided to us. We should check that it is of good quality. 

Apart from the first style observed on the line, the sum of the running days should equal N*(N+1)/2. This can easily be tested by looping through dasta grouped by line_code/style.

The Good styles object is a counter of how many line/style group have running days data that conform to the expected paradigm. The BadStyles object is a list that includes the style name for each line/style group that has running days data that does not conform to the expected paradigm. The ExcludedCounter is an object that states how many line/style groups were excluded from the analysis by reason of having the start date of the data in the Date data asssociated with the group. The sum of GoodStyles, len(BadRuns) and ExcludedCounter should exactly equal the number of groups.