question: public static boolean checkInstanceOf ( CharSequence targetClassName , CharSequence referenceClassName ) { if ( ( targetClassName == null ) || ( referenceClassName == null ) ) return false ; if ( TextUtils . equals ( targetClassName , referenceClassName ) ) return true ; final Class < ? > referenceClass = loadOrGetCachedClass ( referenceClassName . toString ( ) ) ; final Class < ? > targetClass = loadOrGetCachedClass ( targetClassName . toString ( ) ) ; return referenceClass != null && targetClass != null && referenceClass . isAssignableFrom ( targetClass ) ; }
target:  Returns whether a target class is an instance of a reference class.