Finish challenge 14.

src/bytes.rs

@@ -6,6 +6,10 @@ use std::fmt::Write; // need to import this trait
 pub struct Bytes(pub Vec<u8>);
 
 impl Bytes {
+    pub fn empty() -> Bytes {
+        Bytes(vec![])
+    }
+
     pub fn from_utf8(s: &str) -> Bytes {
         Bytes(s.as_bytes().iter().map(|c| c.clone()).collect())
     }
@@ -16,6 +20,10 @@ impl Bytes {
         String::from(std::str::from_utf8(&v).unwrap())
     }
 
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
     pub fn get_block(&self, block_index: usize, block_size: usize) -> Bytes {
         Bytes(self.0[(block_index * block_size)..(block_index + 1) * block_size].to_vec())
     }