diff --git a/src/name-assignments/assignment-hash.hpp b/src/name-assignments/assignment-hash.hpp
index 8ff253f..9054bb7 100644
--- a/src/name-assignments/assignment-hash.hpp
+++ b/src/name-assignments/assignment-hash.hpp
@@ -13,11 +13,12 @@
 /**
  * assign names base on client probe parameter
  */
-class AssignmentHash: public NameAssignmentFuncFactory{
+class AssignmentHash: public NameAssignmentFuncFactory {
 public:
-  AssignmentHash();
+  AssignmentHash(const std::string& format = "");
 
-  NameAssignmentFunc getFunction(const std::string &factoryParam) override;
+  std::vector<PartialName>
+  assignName(const std::vector<std::tuple<std::string, std::string>>& params) override;
 
 };
 }