wallet: when sweeping, do network reqs in parallel, and don't block GUI

electrum/tests/test_wallet_vertical.py

@@ -1404,6 +1404,11 @@ class TestWalletSending(TestCaseForTestnet):
                     return [{'tx_hash': 'ac24de8b58e826f60bd7b9ba31670bdfc3e8aedb2f28d0e91599d741569e3429', 'tx_pos': 1, 'height': 1325785, 'value': 1000000}]
                 else:
                     return []
+            async def get_transaction(self, txid):
+                if txid == "ac24de8b58e826f60bd7b9ba31670bdfc3e8aedb2f28d0e91599d741569e3429":
+                    return "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"
+                else:
+                    raise Exception("unexpected txid")
 
         privkeys = ['93NQ7CFbwTPyKDJLXe97jczw33fiLijam2SCZL3Uinz1NSbHrTu', ]
         network = NetworkMock()