src/main/java/io/github/glytching/junit/extension/folder/TemporaryFolder.java
public File createDirectory(String directoryName) {
    Path path = Paths.get(rootFolder.getPath(), directoryName);
    try {
      return Files.createDirectory(path).toFile();
    } catch (IOException ex) {
      throw new TemporaryFolderException(
          String.format("Failed to create directory: '%s'", path.toString()), ex);
    }
  }
public File createDirectory(String directoryName) {
    Path path = Paths.get(rootFolder.getPath(), directoryName);
    try {
      return Files.createDirectory(path).toFile();
    } catch (IOException ex) {
      throw new TemporaryFolderException(
          String.format("Failed to create directory: '%s'", path.toString()), ex);
    }
  }
Create a directory within the temporary folder root.

@param directoryName the name of the directory to be created
@return the directory instance