def get_folders(self):
        attribute_folders, fact_folders = [], []
        for column in self.get_columns():
            if column.folder:
                if isinstance(column, (Attribute, Label, ConnectionPoint, Reference, Date)):
                    if (column.folder, column.folder_title) not in attribute_folders:
                        attribute_folders.append((column.folder, column.folder_title))
                if isinstance(column, (Fact, Date)):
                    if fact_folders not in (column.folder, column.folder_title):
                        fact_folders.append((column.folder, column.folder_title))
        return attribute_folders, fact_folders
dataset/ETHPy150Open comoga/gooddata-python/gooddataclient/dataset.py/Dataset.get_folders/swapped operands of `not in`