question: @ Override @ Nullable protected Object extractParameter ( @ Nullable String cacheName , String typeName , TypeKind typeKind , String fldName , Object obj ) throws CacheException { switch ( typeKind ) { case BUILT_IN : return obj ; case POJO : return extractPojoParameter ( cacheName , typeName , fldName , obj ) ; default : return extractBinaryParameter ( fldName , obj ) ; } }
target:  Get field value from object for use as query parameter.