code: def name(self):
      return "ToGrayscale"
  
file_path: evadb/evadb/functions/ndarray/to_grayscale.py
imports: import numpy
  import pandas
  from evadb.catalog.catalog_type import NdArrayType
  from evadb.functions.abstract.abstract_function import AbstractFunction
  from evadb.functions.decorators.decorators import forward, setup
  from evadb.functions.decorators.io_descriptors.data_types import PandasDataframe
  from evadb.utils.generic_utils import try_to_import_cv2
label_desc: Use image node_id 2 for calling the ToGrayscale obj's underlying member method code with example usage: obj.name() and returns: str