REPORT-45689 添加注解

designer-base/src/main/java/com/fr/design/mainframe/widget/wrappers/MobileParamWrapper.java

@@ -4,6 +4,7 @@ import com.fr.design.Exception.ValidationException;
 import com.fr.design.designer.properties.Decoder;
 import com.fr.design.designer.properties.Encoder;
 import com.fr.locale.InterProviderFactory;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * @author hades
@@ -12,6 +13,7 @@ import com.fr.locale.InterProviderFactory;
  */
 public class MobileParamWrapper implements Encoder, Decoder {
 
+    @Nullable
     @Override
     public Object decode(String txt) {
         return null;