static boolean isBlankNode ( Object v ) { // Note: A value is a blank node if all of these hold true: // 1. It is an Object. // 2. If it has an @id key its value begins with '_:'. // 3. It has no keys OR is not a @value, @set, or @list. if ( v instanceof Map ) { final Map < String , Object > map = ( Map < String , Object > ) v ; if ( map . containsKey ( "@id" ) ) { return ( ( String ) map . get ( "@id" ) ) . startsWith ( "_:" ) ; } else { return map . isEmpty ( ) || ! map . containsKey ( "@value" ) || map . containsKey ( "@set" ) || map . containsKey ( "@list" ) ; } } return false ; }
Returns true if the given value is a blank node .