question: public static Short toShort ( Object o , Short defaultValue ) { if ( o instanceof Short ) return ( Short ) o ; if ( defaultValue != null ) return Short . valueOf ( toShortValue ( o , defaultValue . shortValue ( ) ) ) ; short res = toShortValue ( o , Short . MIN_VALUE ) ; if ( res == Short . MIN_VALUE ) return defaultValue ; return Short . valueOf ( res ) ; }
target:  cast a Object to a Byte Object(reference type)