code: protected File newConfigurationDirectory(final @NonNull String parent,
  		final @NonNull String child)
  	{
  		File configurationDir = new File(parent, child);
  		if (!configurationDir.exists())
  		{
  			configurationDir.mkdir();
  		}
  		return configurationDir;
  	}
docs: Factory method for create a new configuration directory {@link File} object if it is not
  exists. This method is invoked in the constructor and can be overridden from the derived
  classes so users can provide their own version of a new configuration {@link File} object
  
  @param parent
  the parent
  @param child
  the child
  @return the new configuration directory {@link File} object or the existing one