Check if the node is a condtional node where
            there is an external call checked
            Heuristic:
                - The call is a IF node
                - It contains a, external call
                - The condition is the negation (!)

            This will work only on naive implementation

def _filter_if(self, node):
        """
            Check if the node is a condtional node where
            there is an external call checked
            Heuristic:
                - The call is a IF node
                - It contains a, external call
                - The condition is the negation (!)

            This will work only on naive implementation
        """
        return isinstance(node.expression, UnaryOperation)\
            and node.expression.type == UnaryOperationType.BANG