static boolean isNodeReference ( Object v ) { // Note: A value is a subject reference if all of these hold true: // 1. It is an Object. // 2. It has a single key: @id. return ( v instanceof Map && ( ( Map < String , Object > ) v ) . size ( ) == 1 && ( ( Map < String , Object > ) v ) . containsKey ( "@id" ) ) ; }
Returns true if the given value is a subject reference .