lib: Add variable for header

Signed-off-by: Patrick José Pereira <[email protected]>

src/lib.rs

@@ -15,8 +15,8 @@ pub struct PingMessagePack([u8; 1 + Self::HEADER_SIZE + PAYLOAD_SIZE + 2]);
 impl Default for PingMessagePack {
     fn default() -> Self {
         let mut new = Self([0; 1 + Self::HEADER_SIZE + PAYLOAD_SIZE + 2]);
-        new.0[0] = 'B' as u8;
-        new.0[1] = 'R' as u8;
+        new.0[0] = Self::HEADER[0];
+        new.0[1] = Self::HEADER[1];
         new
     }
 }
@@ -41,7 +41,8 @@ impl TryFrom<&Vec<u8>> for Messages {
 
     fn try_from(buffer: &Vec<u8>) -> Result<Self, Self::Error> {
         // Parse start1 and start2
-        if !((buffer[0] == b'B') && (buffer[1] == b'R')) {
+        if !((buffer[0] == PingMessagePack::HEADER[0]) && (buffer[1] == PingMessagePack::HEADER[1]))
+        {
             return Err("Message should start with \"BR\" ASCII sequence");
         }
 
@@ -93,6 +94,7 @@ impl PingMessagePack {
      */
 
     const HEADER_SIZE: usize = 8;
+    const HEADER: [u8; 2] = ['B' as u8, 'R' as u8];
 
     pub fn new() -> Self {
         Default::default()