match fields marshal

src/etherparser/net/mac_address.rs

+use byteorder::WriteBytesExt;
+
 pub struct MacAddr {
     mac: [u8; 6],
 }
@@ -8,6 +10,14 @@ impl MacAddr {
     }
 }
 
+impl MacAddr {
+    pub fn marshal(&self, bytes: &mut Vec<u8>) {
+        for m in self.mac.iter() {
+            bytes.write_u8(*m);
+        }
+    }
+}
+
 impl From<MacAddr> for u64 {
     fn from(value: MacAddr) -> Self {
         let mut byte: u64 = 0;