code: @SuppressWarnings("null")
  	public static String value(Class<?> clazz, String key, String defaultValue) {
  		return System.getProperty(clazz.getName() + key, defaultValue);
  	}
docs: Gets a system property value.
  
  @param clazz the {@linkplain Class} to derive the property key from.
  @param key the property key (relative to the submitted {@linkplain Class}) to get.
  @param defaultValue the default value to return in case the property is not defined.
  @return the property value or the submitted default value if the property is not defined.