function tryGetCharPref(prefName, defaultValue) {
	if (prefs.prefHasUserValue(prefName)) {
		return prefs.getCharPref(prefName);
	}
	return defaultValue;
}
/**
 * Try to get a the user value of a preference
 *
 * @param {string} prefName
 * @param {string} defaultValue - default value if no user value exists
 * @returns {string}
 */
Try to get a the user value of a preference
@param {string} prefName
@param {string} defaultValue - default value if no user value exists
@returns {string}
Try to get a the user value of a preference @param { string } prefName @param { string } defaultValue - default value if no user value exists @returns { string }
function tryGetCharPref(prefName, defaultValue) {
	if (prefs.prefHasUserValue(prefName)) {
		return prefs.getCharPref(prefName);
	}
	return defaultValue;
}
function tryGetCharPref ( prefName , defaultValue ) { if ( prefs . prefHasUserValue ( prefName ) ) { return prefs . getCharPref ( prefName ) ; } return defaultValue ; }
Try to get a the user value of a preference
 @param {string} prefName
 @param {string} defaultValue - default value if no user value exists
 @returns {string}
Try to get a the user value of a preference @param { string } prefName @param { string } defaultValue - default value if no user value exists @returns { string }