code: def _filter_if(self, node):
          
          return isinstance(node.expression, UnaryOperation)\
              and node.expression.type == UnaryOperationType.BANG
docs: 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