create constructors for VmcExtVrm

src/lib.rs

@@ -1328,7 +1328,7 @@ impl VmcExtLight {
 }
 
 #[derive(Debug)]
-struct VmcExtVrm {
+pub struct VmcExtVrm {
     path: String,
     title: String,
     hash: Option<String>,
@@ -1376,6 +1376,18 @@ impl VmcMessage for VmcExtVrm {
     }
 }
 
+impl VmcExtVrm {
+    pub fn new(path: String, title: String, hash: Option<String>) ->MsgNewResult<Self> {
+        Ok(Self { path, title, hash})
+    }
+    pub fn new_vmc_message(path: String, title: String, hash: Option<String>) ->TraitMsgNewResult {
+        match Self::new(path, title, hash) {
+            Ok(val) => Ok(Box::new(val)),
+            Err(val) => Err(val)
+        }
+    }
+}
+
 #[derive(Debug)]
 struct VmcExtRemote {
     service: String,