code: def build_validation_data_loader(self) -> keras.InputData:
      # Ignore header line and read the test CSV observations into a pandas DataFrame.
      test = pd.read_csv(
          self.context.get_data_config()["test_url"],
          names=DS_COLUMNS,
          header=0,
      )
      test_features, test_labels = test, test.pop(LABEL_HEADER)
  
      # Since we're building a classifier, convert the labels in the raw
      # dataset (0, 1, or 2) to one-hot vector encodings that we'll to
      # construct the Sequence data loaders that Determined expects.
      test_labels_categorical = to_categorical(
          test_labels, num_classes=3
      )
  
      return test_features.values, test_labels_categorical
  
file_path: determined/examples/computer_vision/iris_tf_keras/model_def.py
imports: from typing import List
  import pandas
  import tensorflow
  from tensorflow.keras.layers import Dense, Input
  from tensorflow.keras.losses import categorical_crossentropy
  from tensorflow.keras.metrics import categorical_accuracy
  from tensorflow.keras.models import Model
  from tensorflow.keras.optimizers.legacy import RMSprop
  from tensorflow.keras.utils import to_categorical
  from determined import keras
label_desc: Use image node_id 5 for calling the IrisTrial obj's underlying member method code with example usage: obj.build_validation_data_loader() and returns: test_features,  test_labels_categorical