code: def config_cython():
      
      if not with_cython:
          return []
      # pylint: disable=unreachable
      if os.name == 'nt':
          print("WARNING: Cython is not supported on Windows, will compile without cython module")
          return []
  
      try:
          from Cython.Build import cythonize
          # from setuptools.extension import Extension
          if sys.version_info >= (3, 0):
              subdir = "_cy3"
          else:
              subdir = "_cy2"
          ret = []
          path = "mxnet/cython"
          if os.name == 'nt':
              library_dirs = ['mxnet', '../build/Release', '../build']
              libraries = ['libmxnet']
          else:
              library_dirs = None
              libraries = None
  
          for fn in os.listdir(path):
              if not fn.endswith(".pyx"):
                  continue
              ret.append(Extension(
                  "mxnet/%s/.%s" % (subdir, fn[:-4]),
                  ["mxnet/cython/%s" % fn],
                  include_dirs=["../include/", "../3rdparty/tvm/nnvm/include"],
                  library_dirs=library_dirs,
                  libraries=libraries,
                  language="c++"))
          return cythonize(ret)
      except ImportError:
          print("WARNING: Cython is not installed, will compile without cython module")
          return []
docs: Try to configure cython and return cython configuration