question: public Metadata . Builder clear ( ) { Metadata_Builder _defaults = new Metadata . Builder ( ) ; type = _defaults . type ; interfaceType = _defaults . interfaceType ; optionalBuilder = _defaults . optionalBuilder ; builderFactory = _defaults . builderFactory ; generatedBuilder = _defaults . generatedBuilder ; valueType = _defaults . valueType ; partialType = _defaults . partialType ; visibleNestedTypes . clear ( ) ; propertyEnum = _defaults . propertyEnum ; properties . clear ( ) ; standardMethodUnderrides . clear ( ) ; builderSerializable = _defaults . builderSerializable ; generatedBuilderAnnotations . clear ( ) ; valueTypeAnnotations . clear ( ) ; valueTypeVisibility = _defaults . valueTypeVisibility ; nestedClasses . clear ( ) ; _unsetProperties . clear ( ) ; _unsetProperties . addAll ( _defaults . _unsetProperties ) ; return ( Metadata . Builder ) this ; }
target:  Resets the state of this builder.