code: def maybe_cythonize_extensions(top_path, config):
      """Tweaks for building extensions between release and development mode."""
      is_release = os.path.exists(os.path.join(top_path, "PKG-INFO"))
  
      if is_release:
          build_from_c_and_cpp_files(config.ext_modules)
      else:
          message = (
              "Please install cython with a version >= {0} in order "
              "to build a scikit-learn development version."
          ).format(CYTHON_MIN_VERSION)
          try:
              import Cython
  
              if LooseVersion(Cython.__version__) < CYTHON_MIN_VERSION:
                  message += " Your version of Cython was {0}.".format(
                      Cython.__version__
                  )
                  raise ValueError(message)
              from Cython.Build import cythonize
          except ImportError as exc:
              exc.args += (message,)
              raise
  
          config.ext_modules = cythonize(config.ext_modules)
  
imports: from __future__ import division, print_function, absolute_import
  import os
  from distutils.version import LooseVersion
  from numpy.distutils.system_info import get_info
label_desc: Use image node_id 3 for calling a global function with example usage: maybe_cythonize_extensions(top_path, config) without return types