def __len__(self):
        """
        sum of MIS=X ops shall equal the sequence length.
        """
        return sum(l for l, op,in self.items() \
                               if op in Cigar.read_consuming_ops)
def __len__ ( self ) : return sum ( l for l , op , in self . items ( ) if op in Cigar . read_consuming_ops )
sum of MIS=X ops shall equal the sequence length.