diff --git a/gateway/gateway.py b/gateway/gateway.py
index 2b6fe3111bc3d8ebea27902554a4d158a5effcbb..312b221ecece706db5c025062c193935f8cb558f 100644
--- a/gateway/gateway.py
+++ b/gateway/gateway.py
@@ -153,9 +153,9 @@ class Gateway:
     def get_tx_input(self, contract, tx):
         return contract.decode_function_input(tx.input)
 
-    def transaction_is_canonical(self, transaction):
+    def block_is_canonical_poa(self, block_number):
         last_block_number = self.get_last_blocknumber()
-        tx_block_number = transaction.blockNumber
+        tx_block_number = block_number
         required_block_difference = math.ceil(self.get_signers_count() / 2) + 1
         return (last_block_number - tx_block_number) > required_block_difference
 
@@ -328,3 +328,9 @@ class HTTPFastLogSearcher:
                 for i in v:
                     res.append(i)
             return res
+
+
+class AddressValidation:
+
+    def is_valid(self, address):
+        return Web3.isAddress(address)