create constructors for VmcExtOpt

src/lib.rs

@@ -1438,7 +1438,7 @@ impl VmcExtRemote {
 }
 
 #[derive(Debug)]
-struct VmcExtOpt {
+pub struct VmcExtOpt {
     option: String,
 }
 
@@ -1467,6 +1467,18 @@ impl VmcMessage for VmcExtOpt {
     }
 }
 
+impl VmcExtOpt {
+    pub fn new(option: String) ->MsgNewResult<Self> {
+        Ok(Self { option })
+    }
+    pub fn new_vmc_message(option: String) -> TraitMsgNewResult {
+        match Self::new(option) {
+            Ok(val) => Ok(Box::new(val)),
+            Err(val) => Err(val)
+        }
+    }
+}
+
 #[derive(Debug)]
 struct VmcExtSettingColor {
     color: Color,