Clarify comment

Signed-off-by: Ana Hobden <operator@hoverbear.org>

Author: Hoverbear

src/lib.rs

@@ -599,6 +599,16 @@ pub type KvFuture<Resp> = Box<dyn Future<Item = Resp, Error = Error>>;
 /// which means all of the above types can be passed directly to those functions.
 pub trait KeyRange: Sized {
     fn into_bounds(self) -> (Bound<Key>, Bound<Key>);
+    /// Return the keys that match the given bounds, inclusively.
+    ///
+    /// ```rust
+    /// use tikv_client::{KeyRange, Key};
+    /// let range = vec![0]..vec![100];
+    /// assert_eq!(
+    ///     range.into_keys().unwrap(),
+    ///     (Key::from(vec![0]), Some(Key::from(vec![99])))
+    /// );
+    // ```
     fn into_keys(self) -> Result<(Key, Option<Key>)> {
         range_to_keys(self.into_bounds())
     }

src/rpc/tikv/client.rs

@@ -558,12 +558,14 @@ impl KvClient {
             .unwrap();
         end_key
             .map(|k| {
-                // Scan in TiKV has a weird particularity to it.
-                // The **start** of a scan is inclusive, unless appended with an '\0', then it is exclusive.
-                // The **end** of a scan is exclusive, unless appended with an '\0', then it is inclusive.
+                // Scan in TiKV has a particularity to it.
                 //
-                // We work around this behavior in this client by making all our scans (Inclusive, Inclusive),
-                // if we have exclusive bounds our own bounds calculation adjusts it.
+                // The **start** of a scan is inclusive, unless appended with an '\0', then it is
+                // exclusive. The **end** of a scan is exclusive, unless appended with an '\0',
+                // then it is inclusive.
+                //
+                // Because of `KeyRange::into_keys()` we *know* the keys we have are inclusive
+                // (KeyRange calculates it).
                 let mut end_key = k.into_inner();
                 end_key.append(&mut vec![0]);
                 req.set_end_key(end_key);