test: Remove unused, undocumented and misleading CScript.__add__

test/functional/test_framework/script.py

@@ -449,15 +449,8 @@ class CScript(bytes):
         return other
 
     def __add__(self, other):
-        # Do the coercion outside of the try block so that errors in it are
-        # noticed.
-        other = self.__coerce_instance(other)
-
-        try:
-            # bytes.__add__ always returns bytes instances unfortunately
-            return CScript(super(CScript, self).__add__(other))
-        except TypeError:
-            raise TypeError('Can not add a %r instance to a CScript' % other.__class__)
+        # add makes no sense for a CScript()
+        raise NotImplementedError
 
     def join(self, iterable):
         # join makes no sense for a CScript()

test/functional/test_framework/script_util.py

@@ -23,3 +23,4 @@ from test_framework.script import CScript
 # scriptPubKeys are needed, to guarantee that the minimum transaction size is
 # met.
 DUMMY_P2WPKH_SCRIPT = CScript([b'a' * 21])
+DUMMY_2_P2WPKH_SCRIPT = CScript([b'b' * 21])