code: def column_udf_class(col, udf):
      class UDFClass:
          def __call__(self, row):
              return {col: udf(row[col])}
  
      return UDFClass
  
file_path: ray/python/ray/data/tests/util.py
imports: import functools
  import os
  import tempfile
  from contextlib import contextmanager
  import ray
  from ray.data._internal.execution.interfaces.physical_operator import DataOpTask, MetadataOpTask, PhysicalOperator
label_desc: Use image node_id 3 for calling a global function with example usage: column_udf_class(col, udf) and returns: UDFClass, dict