code: def __str__(self) -> str:
      expr_str = ""
      if not isinstance(self._value, np.ndarray):
          expr_str = f"{str(self._value)}"
      else:
          expr_str = f"{np.array_str(self._value)}"
      return expr_str
  
file_path: evadb/evadb/expression/constant_value_expression.py
imports: from typing import Any
  import numpy
  import pandas
  from evadb.catalog.catalog_type import ColumnType
  from evadb.expression.abstract_expression import AbstractExpression, ExpressionType
  from evadb.models.storage.batch import Batch
label_desc: Use image node_id 7 for calling the ConstantValueExpression obj's underlying member method code with example usage: obj.__str__() and returns: expr_str