Resolve "Operation Replacement in a SFG"

Added method with tests for replacing multiple operations in a sfg with another operation with the same amount of input / output ports. Closes #17

b_asic/signal_flow_graph.py

@@ -406,14 +406,15 @@ class SFG(AbstractOperation):
         return self()
 
     def replace_operations(self, inputs: Sequence[Input], outputs: Sequence[Output], operation: Operation):
-        """Replace one or more operations in the sfg with a operation that have same number of inputs and outputs.
-        Then return a new deepcopy of the sfg.
+        """Replace multiple operations in the sfg with a operation of equivalent functionallity with the same number of inputs and outputs.
+        Then return a new deepcopy of the sfg with the replaced operations.
 
         Arguments:
-        inputs: The inputs for the operations we are replacing.
-        outputs: The outputs for the operations we are replacing.
-        operation: The replacing operation.
+        inputs: The inputs of the operations we are replacing.
+        outputs: The outputs of the operations we are replacing.
+        operation: The operation used for replacement.
         """
+        return self()
 
     def _evaluate_source(self, src: OutputPort, results: MutableResultMap, registers: MutableRegisterMap, prefix: str) -> Number:
         src_prefix = prefix