code: def _get_var(self, name, conf_desc):
      hook, envvar, confvar, convert, append = conf_desc
      if convert is None:
          convert = lambda x: x
      var = self._hook_handler(name, hook)
      if envvar is not None:
          envvar_contents = os.environ.get(envvar)
          if envvar_contents is not None:
              envvar_contents = convert(envvar_contents)
              if var and append:
                  if (
                      os.environ.get("NPY_DISTUTILS_APPEND_FLAGS", "0")
                      == "1"
                  ):
                      var.extend(envvar_contents)
                  else:
                      var = envvar_contents
                      if (
                          "NPY_DISTUTILS_APPEND_FLAGS"
                          not in os.environ.keys()
                      ):
                          msg = (
                              "{} is used as is, not appended ".format(
                                  envvar
                              )
                              + "to flags already defined "
                              + "by numpy.distutils! Use NPY_DISTUTILS_APPEND_FLAGS=1 "
                              + "to obtain appending behavior instead (this "
                              + "behavior will become default in a future release)."
                          )
                          warnings.warn(msg, UserWarning, stacklevel=3)
              else:
                  var = envvar_contents
      if confvar is not None and self._conf:
          if confvar in self._conf:
              source, confvar_contents = self._conf[confvar]
              var = convert(confvar_contents)
      return var
  
file_path: catboost/contrib/python/numpy/py2/numpy/distutils/fcompiler/environment.py
imports: from __future__ import division, absolute_import, print_function
  import os
  import warnings
  from distutils.dist import Distribution
label_desc: Use image node_id 6 for calling the EnvironmentConfig obj's underlying member method code with example usage: obj._get_var(name, conf_desc) and returns: var