Sessions.

crates/utils/src/codec/leb128.rs

@@ -178,3 +178,9 @@ impl_unsigned_leb128!(u16, [0, 7, 14]);
 impl_unsigned_leb128!(u32, [0, 7, 14, 21, 28]);
 impl_unsigned_leb128!(u64, [0, 7, 14, 21, 28, 35, 42, 49, 56, 63]);
 impl_unsigned_leb128!(usize, [0, 7, 14, 21, 28, 35, 42, 49, 56, 63]);
+
+impl Leb128Writer for Vec<u8> {
+    fn write_leb128<T: Leb128_>(&mut self, value: T) -> std::io::Result<usize> {
+        T::to_leb128_writer(value, self)
+    }
+}