diff --git a/src/mrds/trees/unbalanced.rs b/src/mrds/trees/unbalanced.rs
index 1ec6b8f..7cdde8c 100644
--- a/src/mrds/trees/unbalanced.rs
+++ b/src/mrds/trees/unbalanced.rs
@@ -144,30 +144,6 @@ impl<'a, T: Monad<'a>, A: 'a + Send + Sync> UnbalancedConstructor<'a, T, A> {
         let ctr = self.clone();
         UnbalancedTree::Node(Arc::new(UnbalancedReference((ctr.wrap)(node)))).into()
     }
-
-    #[cfg(test)]
-    pub fn from_slice<R: 'a + rand::Rng>(
-        self: &Arc<Self>,
-        rng: &mut R,
-        slice: &[A],
-    ) -> Arc<UnbalancedTree<'a, T, A>>
-    where
-        A: 'a + Clone,
-    {
-        if slice.is_empty() {
-            self.leaf()
-        } else {
-            let key_at = rng.gen_range(0..slice.len());
-            let key = slice[key_at].clone();
-            let lslice = &slice[..key_at];
-            let rslice = &slice[key_at + 1..];
-            self.clone().node(
-                self.clone().from_slice(rng, lslice),
-                key,
-                self.clone().from_slice(rng, rslice),
-            )
-        }
-    }
 }
 
 #[cfg(test)]
@@ -178,6 +154,36 @@ mod tests {
 
     use super::{algorithms::contains::*, algorithms::subset::*, *};
 
+    trait FromSlice<R> {
+        type Tree;
+        type A;
+
+        fn from_slice(self: &Arc<Self>, rng: &mut R, slice: &[Self::A]) -> Arc<Self::Tree>;
+    }
+
+    impl<'a, T: Monad<'a>, A: 'a + Send + Sync + Clone, R: 'a + rand::Rng> FromSlice<R>
+        for UnbalancedConstructor<'a, T, A>
+    {
+        type A = A;
+        type Tree = UnbalancedTree<'a, T, A>;
+
+        fn from_slice(self: &Arc<Self>, rng: &mut R, slice: &[Self::A]) -> Arc<Self::Tree> {
+            if slice.is_empty() {
+                self.leaf()
+            } else {
+                let key_at = rng.gen_range(0..slice.len());
+                let key = slice[key_at].clone();
+                let lslice = &slice[..key_at];
+                let rslice = &slice[key_at + 1..];
+                self.clone().node(
+                    self.clone().from_slice(rng, lslice),
+                    key,
+                    self.clone().from_slice(rng, rslice),
+                )
+            }
+        }
+    }
+
     #[test]
     fn test_simple_slices() {
         let ctr: Arc<UnbalancedConstructor<instances::result::ResultInstance<()>, _>> =
@@ -265,7 +271,6 @@ mod tests {
             UnbalancedConstructor::rc(Box::new(|node| {
                 Box::new(move || TracedMonad::pure(node.clone()).after_resolution())
             }));
-        // let mut rng = rand::thread_rng();
         let mut rng = rand::rngs::StdRng::seed_from_u64(426);
         let big: Vec<i32> = (0..(rng.gen_range(1000..2000))).collect();
         let key = big[rng.gen_range(0..big.len())];
@@ -284,6 +289,5 @@ mod tests {
             None,
         );
         assert!(traced.value.is_ok());
-        // panic!("{:?}", traced.render().to_vec());
     }
 }