code: def train_data():
      bunch = load_diabetes()
      X, y = bunch.data, bunch.target
      y = np.round(y, decimals=-2)
      return X, y
  
file_path: lightning/lightning/impl/tests/test_prank.py
imports: import numpy
  import pytest
  from sklearn.datasets import load_diabetes
  from lightning.ranking import PRank
  from lightning.ranking import KernelPRank
label_desc: Use image node_id 1 for calling a global function with example usage: train_data() and returns: X,  y