code: def __str__(self) -> str:
      expr_str = ""
      if self.table_alias:
          expr_str += f"{str(self.table_alias)}."
      if self.name:
          expr_str += f"{str(self.name)}"
      if self.col_alias:
          expr_str += f" AS {str(self.col_alias)}"
      expr_str += ""
      return expr_str
  
imports: from typing import Union
  from evadb.catalog.models.column_catalog import ColumnCatalogEntry
  from evadb.catalog.models.function_io_catalog import FunctionIOCatalogEntry
  from evadb.models.storage.batch import Batch
  from .abstract_expression import AbstractExpression, ExpressionReturnType, ExpressionType
label_desc: Use image node_id 12 for calling the TupleValueExpression obj's underlying member method code with example usage: obj.__str__() and returns: expr_str