diff --git a/src/levanter/data/_prp.py b/src/levanter/data/_prp.py
index af6d82817..59170fbd3 100644
--- a/src/levanter/data/_prp.py
+++ b/src/levanter/data/_prp.py
@@ -1,11 +1,9 @@
 import typing
 
-import jax.numpy as jnp
-import jax.random as jrandom  # Import jax.random
+import jax.random as jrandom
 import numpy as np
 
 
-# TODO: do we make this a pytree
 class Permutation:
     # Pseudo-Random Permutation Code
     """A stateless pseudo-random permutation.
@@ -21,8 +19,10 @@ class Permutation:
     def __init__(self, length, prng_key):
         self.length = length
         # Convert jax.random.PRNGKey to numpy.random.Generator
-        self.rng = np.random.Generator(np.random.PCG64(jrandom.randint(prng_key, (), 0, 2**32).item())) # Use jrandom.randint
-        self.a, self.b = self._generate_permutation_params() # Generate a and b in init
+        self.rng = np.random.Generator(
+            np.random.PCG64(jrandom.randint(prng_key, (), 0, 2**32).item())
+        )  # Use jrandom.randint
+        self.a, self.b = self._generate_permutation_params()  # Generate a and b in init
 
     def _generate_permutation_params(self):
         length = self.length
@@ -36,7 +36,6 @@ def _generate_permutation_params(self):
         b = rng.integers(0, length)  # b can be in [0, length-1]
         return a, b
 
-
     @typing.overload
     def __call__(self, indices: int) -> int:
         ...
@@ -61,7 +60,7 @@ def __call__(self, indices):
             indices = np.array(indices)
             was_int = True
 
-        out = (a * indices + b) % length # Compute permutation on-the-fly
+        out = (a * indices + b) % length  # Compute permutation on-the-fly
 
         if was_int:
             return int(out)