code: def estimate_inmemory_data_size(self) -> Optional[int]:
      return self._estimate_inmemory_data_size
  
file_path: ray/python/ray/data/datasource/databricks_uc_datasource.py
imports: import json
  import logging
  import os
  import time
  from typing import List, Optional
  from urllib.parse import urljoin
  import numpy
  import pyarrow
  import requests
  from ray.data.block import BlockMetadata
  from ray.data.datasource.datasource import Datasource, ReadTask
  from ray.util.annotations import PublicAPI
label_desc: Use image node_id 2 for calling the DatabricksUCDatasource obj's underlying member method code with example usage: obj.estimate_inmemory_data_size() and returns: self