code: def _check_eigen_source():
      eigen_src = Path("sksurv/linear_model/src/eigen/Eigen")
      if not eigen_src.is_dir():
          raise RuntimeError(
              f"{eigen_src.resolve()} directory not found. You might have to run 'git submodule update --init'."
          )
  
file_path: scikit-survival/setup.py
imports: import os
  from pathlib import Path
  import shutil
  import sys
  from packaging.version import Version
  from setuptools import Command, Extension, setup
label_desc: Use image node_id 4 for calling a global function with example usage: _check_eigen_source() without return types