fix method order in Butterfly

b_asic/core_operations.py

@@ -223,9 +223,9 @@ class Butterfly(AbstractOperation):
     def __init__(self, src0: Optional[SignalSourceProvider] = None, src1: Optional[SignalSourceProvider] = None, name: Name = ""):
         super().__init__(input_count = 2, output_count = 2, name = name, input_sources = [src0, src1])
 
-    def evaluate(self, a, b):
-        return a + b, a - b
-
     @property
     def type_name(self) -> TypeName:
         return "bfly"
+
+    def evaluate(self, a, b):
+        return a + b, a - b