code: def get_linear_data(a=2, b=5, size=None):
      x = np.arange(0, 10, 10 / size, dtype=np.float32)
      y = a * x + b
      return x, y
  
file_path: BigDL/python/orca/test/bigdl/orca/automl/model/test_base_keras_model.py
imports: from unittest import TestCase
  from bigdl.orca.automl.model.base_keras_model import KerasBaseModel, KerasModelBuilder
  import numpy
  import tensorflow
  import pytest
label_desc: Use image node_id 1 for calling a global function with example usage: get_linear_data(a, b, size) and returns: x,  y