Remove misc dead code in libs/

libs/utils/src/vec_map.rs

@@ -120,32 +120,6 @@ impl<K: Ord, V> VecMap<K, V> {
         Ok((None, delta_size))
     }
 
-    /// Split the map into two.
-    ///
-    /// The left map contains everything before `cutoff` (exclusive).
-    /// Right map contains `cutoff` and everything after (inclusive).
-    pub fn split_at(&self, cutoff: &K) -> (Self, Self)
-    where
-        K: Clone,
-        V: Clone,
-    {
-        let split_idx = self
-            .data
-            .binary_search_by_key(&cutoff, extract_key)
-            .unwrap_or_else(std::convert::identity);
-
-        (
-            VecMap {
-                data: self.data[..split_idx].to_vec(),
-                ordering: self.ordering,
-            },
-            VecMap {
-                data: self.data[split_idx..].to_vec(),
-                ordering: self.ordering,
-            },
-        )
-    }
-
     /// Move items from `other` to the end of `self`, leaving `other` empty.
     /// If the `other` ordering is different from `self` ordering
     /// `ExtendOrderingError` error will be returned.