CurrentUserType.observable()CurrentUserType.observable()String to a Boolean, or null if the boolean cannot be parsed.String to an Integer, or null if the integer cannot be parsed.Double to a String, can be null if the double is also null.Float to a String, can be null if the float is also null.Integer to a String, can be null if the integer is also null.Long to a String, can be null if the long is also null.