code: public static boolean booleanValue(String key, boolean defaultValue) {
  		String value = System.getProperty(key);
  		boolean booleanValue = defaultValue;
  
  		if (value != null) {
  			booleanValue = Boolean.parseBoolean(value);
  		}
  		return booleanValue;
  	}
docs: Gets a {@code boolean} system property value.
  
  @param key the property key to retrieve.
  @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.