public Object read(Object target, ExecutionContext executionContext)
      throws NameNotFoundException, QueryInvocationTargetException {
    if (target == null || target == QueryService.UNDEFINED) {
      return QueryService.UNDEFINED;
    }

    if (target instanceof InternalPdxInstance) {
      return readPdx((InternalPdxInstance) target, executionContext);
    }

    // for non pdx objects
    return readReflection(target, executionContext);
  }
Validate whether this attribute <i>can</i> be evaluated for target type
geode-core/src/main/java/org/apache/geode/cache/query/internal/AttributeDescriptor.java