code: def runtime_library_dir_option(self, dir):
      if sys.platform[:3] == "aix" or sys.platform == "win32":
          # Linux/Solaris/Unix support RPATH, Windows and AIX do not
          raise NotImplementedError
  
      # TODO: could use -Xlinker here, if it's supported
      assert "," not in dir
  
      sep = "," if sys.platform == "darwin" else "="
      return "-Wl,-rpath%s%s" % (sep, dir)
  
imports: from __future__ import division, absolute_import, print_function
  import re
  import os
  import sys
  import warnings
  import platform
  import tempfile
  import hashlib
  import base64
  import subprocess
  from subprocess import Popen, PIPE, STDOUT
  from numpy.distutils.exec_command import filepath_from_subprocess_output
  from numpy.distutils.fcompiler import FCompiler
  from numpy.distutils.compat import get_exception
  from numpy.distutils.system_info import system_info
label_desc: Use image node_id 12 for calling the GnuFCompiler obj's underlying member method code with example usage: obj.runtime_library_dir_option(dir) and returns: unknown