test: remove modinv python util helper function

test/functional/test_framework/util.py

@@ -15,7 +15,6 @@ import os
 import random
 import re
 import time
-import unittest
 
 from . import coverage
 from .authproxy import AuthServiceProxy, JSONRPCException
@@ -537,22 +536,3 @@ def find_vout_for_address(node, txid, addr):
         if addr == tx["vout"][i]["scriptPubKey"]["address"]:
             return i
     raise RuntimeError("Vout not found for address: txid=%s, addr=%s" % (txid, addr))
-
-def modinv(a, n):
-    """Compute the modular inverse of a modulo n using the extended Euclidean
-    Algorithm. See https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm#Modular_integers.
-    """
-    return pow(a, -1, n)
-
-class TestFrameworkUtil(unittest.TestCase):
-    def test_modinv(self):
-        test_vectors = [
-            [7, 11],
-            [11, 29],
-            [90, 13],
-            [1891, 3797],
-            [6003722857, 77695236973],
-        ]
-
-        for a, n in test_vectors:
-            self.assertEqual(modinv(a, n), pow(a, n-2, n))