list(Operation): List of the slithir operations

def slithir_operations(self):
        """
            list(Operation): List of the slithir operations
        """
        if self._slithir_operations is None:
            operations = [n.irs for n in self.nodes]
            operations = [item for sublist in operations for item in sublist if item]
            self._slithir_operations = operations
        return self._slithir_operations