def table_alias(self, table_name, create=False):
        current = self.table_map.get(table_name)
        if not create and current:
            alias = current[0]
            self.alias_refcount[alias] += 1
            return alias, False

        # Create a new alias for this table.
        if current:
            alias = '%s%d' % (self.alias_prefix, len(self.alias_map) + 1)
            current.append(alias)
        else:
            # The first occurence of a table uses the table name directly.
            alias = table_name
            self.table_map[alias] = [alias]
        self.alias_refcount[alias] = 1
        self.tables.append(alias)
        return alias, True
mimeData(itemList) -> None        
dataset/ETHPy150Open CollabQ/CollabQ/vendor/django/db/models/sql/query.py/BaseQuery.table_alias--crossover with--dataset/ETHPy150Open VisTrails/VisTrails/vistrails/gui/common_widgets.py/QSearchTreeWidget.mimeData