How to use the cget.util.symlink_dir function in cget

# Install any dependencies first
            self.install_deps(pb, src_dir, test=test, test_all=test_all, generator=generator, insecure=insecure)
            # Setup cmake file
            if pb.cmake: 
                target = os.path.join(src_dir, 'CMakeLists.txt')
                if os.path.exists(target):
                    os.rename(target, os.path.join(src_dir, builder.cmake_original_file))
                shutil.copyfile(pb.cmake, target)
            # Configure and build
            builder.configure(src_dir, defines=pb.define, generator=generator, install_prefix=install_dir, test=test, variant=pb.variant)
            builder.build(variant=pb.variant)
            # Run tests if enabled
            if test or test_all: builder.test(variant=pb.variant)
            # Install
            builder.build(target='install', variant=pb.variant)
            if util.USE_SYMLINKS: util.symlink_dir(install_dir, self.prefix)
            else: util.copy_dir(install_dir, self.prefix)
        self.write_parent(pb, track=track)
        return "Successfully installed {}".format(pb.to_name())

def link(self, pkg):
        pkg = self.parse_pkg_src(pkg)
        pkg_dir = self.get_package_directory(pkg.to_fname())
        unlink_dir = self.get_unlink_directory(pkg.to_fname())
        if os.path.exists(unlink_dir):
            os.rename(unlink_dir, pkg_dir)
            if util.USE_SYMLINKS: util.symlink_dir(os.path.join(pkg_dir, 'install'), self.prefix)
            else: util.copy_dir(os.path.join(pkg_dir, 'install'), self.prefix)
        # Relink dependencies
        for dep in util.ls(self.get_unlink_directory(), os.path.isdir):
            ls = util.ls(self.get_unlink_deps_directory(dep), os.path.isfile)
            if pkg.to_fname() in ls: self.link(dep)