def __isub__(self, other):
        """Subtract the ``other`` `DataQualityFlag` from this one in-place.
        """
        self.known &= other.known
        self.active -= other.active
        self.active &= self.known
        return self
def __isub__ ( self , other ) : self . known &= other . known self . active -= other . active self . active &= self . known return self
Subtract the ``other`` `DataQualityFlag` from this one in-place.