add initialize body for mutation pruner

mythril/laser/ethereum/plugins/mutation_pruner.py

@@ -1,5 +1,8 @@
 from mythril.laser.ethereum.state.annotation import StateAnnotation
 from mythril.laser.ethereum.svm import LaserEVM
+from mythril.laser.ethereum.plugins.signals import PluginSkipWorldState
+from mythril.laser.ethereum.state.global_state import GlobalState
+from mythril.laser.ethereum.transaction.transaction_models import ContractCreationTransaction
 
 
 class MutationAnnotation(StateAnnotation):
@@ -28,4 +31,20 @@ class MutationPruner:
         pass
 
     def initialize(self, symbolic_vm: LaserEVM):
-        pass
+        """Initializes the mutation pruner
+
+        Introduces hooks for SSTORE operations
+        :param symbolic_vm:
+        :return:
+        """
+        @symbolic_vm.pre_hook("SSTORE")
+        def mutator_hook(global_state: GlobalState):
+            global_state.annotate(MutationAnnotation())
+
+        @symbolic_vm.laser_hook("add_world_state")
+        def world_state_filter_hook(global_state: GlobalState):
+            if isinstance(global_state.current_transaction, ContractCreationTransaction):
+                return
+            if len(list(global_state.get_annotations(MutationAnnotation))) == 0:
+                raise PluginSkipWorldState
+