@Target(value=FIELD)
 @Retention(value=RUNTIME)
 @Documented
public @interface NestedConfigurationProperty
@ConfigurationProperties
 object should be treated as if it were a nested type. This annotation has no bearing on
 the actual binding processes, but it is used by the
 spring-boot-configuration-processor as a hint that a field is not bound as a
 single value. When this is specified, a nested group is created for the field and its
 type is harvested.
 This has no effect on collections and maps as these types are automatically identified.