code: def isolated():
    
    global _ISOLATED
    if _ISOLATED is None:
      from pex import vendor
      from pex.common import safe_mkdtemp, Chroot
  
      chroot = Chroot(safe_mkdtemp())
      with _tracer().timed('Isolating pex in {}'.format(chroot)):
        pex_path = os.path.join(vendor.VendorSpec.ROOT, 'pex')
        for root, _, files in os.walk(pex_path):
          for f in files:
            if not f.endswith('.pyc'):
              abs_file_path = os.path.join(root, f)
              relpath = os.path.relpath(abs_file_path, pex_path)
              chroot.copy(abs_file_path, os.path.join('pex', relpath), label='pex')
  
      _ISOLATED = chroot
    return _ISOLATED.path()
docs: Returns a chroot for third_party isolated from the ``sys.path``.
  
    PEX will typically be installed in site-packages flat alongside many other distributions; as such,
    adding the location of the pex distribution to the ``sys.path`` will typically expose many other
    distributions. An isolated chroot can be used as a ``sys.path`` entry to effect only the exposure
    of pex.
  
    :return: The path of the chroot.
    :rtype: str