[tests] don't override __init__() in individual tests

Almost all test scripts currently need to override the __init__()
method. When they do that they need to call into super().__init__() as
the base class does some generic initialization.

This commit makes the base class __init__() call into set_test_params()
method. Individual test cases can override set_test_params() to setup
their test parameters.

1 files changed, 1 insertions, 4 deletions

diff --git a/test/functional/walletbackup.py b/test/functional/walletbackup.py
index 688cd6d0c8..36714164a8 100755
--- a/test/functional/walletbackup.py
+++ b/test/functional/walletbackup.py
@@ -37,11 +37,8 @@ from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import *
 
 class WalletBackupTest(BitcoinTestFramework):
-
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.setup_clean_chain = True
-        self.num_nodes = 4
         # nodes 1, 2,3 are spenders, let's give them a keypool=100
         self.extra_args = [["-keypool=100"], ["-keypool=100"], ["-keypool=100"], []]