Remove unused function

ConflictSet.cpp

@@ -195,7 +195,6 @@ struct Node {
   /* end section that's copied to the next node */
 
   uint8_t *partialKey();
-  size_t size() const;
 
   Type getType() const { return type; }
   int32_t getCapacity() const { return partialKeyCapacity; }
@@ -771,23 +770,6 @@ uint8_t *Node::partialKey() {
   }
 }
 
-size_t Node::size() const {
-  switch (type) {
-  case Type_Node0:
-    return ((Node0 *)this)->size();
-  case Type_Node3:
-    return ((Node3 *)this)->size();
-  case Type_Node16:
-    return ((Node16 *)this)->size();
-  case Type_Node48:
-    return ((Node48 *)this)->size();
-  case Type_Node256:
-    return ((Node256 *)this)->size();
-  default:                   // GCOVR_EXCL_LINE
-    __builtin_unreachable(); // GCOVR_EXCL_LINE
-  }
-}
-
 // A type that's plumbed along the check call tree. Lifetime ends after each
 // check call.
 struct ReadContext {