Hide Series from the Legend when Null
I'm working with a symbol/stacked bar chart which shows 2 metrics. In order to show both the average (as a symbol), and the individual bars broken out by series I've had to calculate each series independently. There are a fixed number of series however this means that even when a series is null it still shows up in the legend - unlike when you just drag a field in as a series.
Is there any way to fix this such that when the series is null for the visual it is excluded from the legend?