})
	if err == nil || IsNotExist(err) {
		return nil
	}

	// EISDIR means that we have a directory, and we need to
	// remove its contents.
	// EPERM or EACCES means that we don't have write permission on
	// the parent directory, but this entry might still be a directory
	// whose contents need to be removed.
	// Otherwise just return the error.

// file or directory.
//
// The path argument contains the argument to Walk as a prefix.
// That is, if Walk is called with root argument "dir" and finds a file
// named "a" in that directory, the walk function will be called with
// argument "dir/a".
//
// The directory and file are joined with Join, which may clean the
// directory name: if Walk is called with the root argument "x/../dir"

	return os.WriteFile(filename, data, perm)
}

// ReadDir reads the directory named by dirname and returns
// a list of fs.FileInfo for the directory's contents,
// sorted by filename. If an error occurs reading the directory,
// ReadDir returns no directory entries along with the error.
//
// Deprecated: As of Go 1.16, [os.ReadDir] is a more efficient and correct choice:

	}

	// Directory, possibly synthesized.
	// Note that file can be nil here: the map need not contain explicit parent directories for all its files.
	// But file can also be non-nil, in case the user wants to set metadata for the directory explicitly.
	// Either way, we need to construct the list of children of this directory.
	var list []mapFileInfo
	var elem string

The go command builds most objects in a temporary directory,
so go clean is mainly concerned with object files left by other
tools or by manual invocations of go build.

If a package argument is given or the -i or -r flag is set,
clean removes the following files from each of the
source directories corresponding to the import paths:

	_obj/            old object directory, left from Makefiles

// explaining why. At the end of a directory, the error is [io.EOF].
//
// If n <= 0, Readdir returns all the FileInfo from the directory in
// a single slice. In this case, if Readdir succeeds (reads all
// the way to the end of the directory), it returns the slice and a
// nil error. If it encounters an error before the end of the
// directory, Readdir returns the FileInfo read until that point
// and a non-nil error.

    /**
     * <p>Returns the settings directory of the build. The settings directory is the directory containing the settings
     * file.</p>
     *
     * @return The settings directory. Never returns null.
     */
    File getSettingsDir();

    /**
     * <p>Returns the root directory of the build. The root directory is the project directory of the root project.</p>
     *

						<!-- logs (empty) -->
						<mapping>
							<directory>${packaging.fess.log.dir}</directory>
						</mapping>
						<!-- temp (empty) -->
						<mapping>
							<directory>${packaging.fess.temp.dir}</directory>
						</mapping>
						<!-- dictionary (empty) -->
						<mapping>
							<directory>${packaging.fess.dictionary.dir}</directory>
							<filemode>755</filemode>
							<username>opensearch</username>

    }

    private static void checkDirectory(File directory) {
        if (directory.exists()) {
            if (!directory.isDirectory()) {
                throw new IllegalArgumentException(String.format("Cache directory %s must be a directory", directory));
            }
            if (!directory.canRead()) {
                throw new IllegalArgumentException(String.format("Cache directory %s must be readable", directory));
            }

        root.sourceDirectories[0].directory == file('mainSources')
        root.resourceDirectories.size() == 1
        root.resourceDirectories[0].directory == file('mainResources')
        root.testDirectories.size() == 1
        root.testDirectories[0].directory == file('testSources')
        root.testResourceDirectories.size() == 1
        root.testResourceDirectories[0].directory == file('testResources')
    }