Pull out resetting partner fields into method

app/models/derived_variables/lettings_log_variables.rb

@@ -248,18 +248,7 @@ private
       self.beds = nil
     end
     if form.start_year_2026_or_later?
-      person_count = hhmemb || 8
-      (2..person_count).each do |i|
-        if send("relat#{i}_changed?") && send("relat#{i}_was") == "P"
-          ((i + 1)..person_count).each do |j|
-            if self["relat#{j}"] == "X"
-              self["relat#{j}"] = nil
-            end
-          end
-        else
-          next
-        end
-      end
+      reset_partner_fields!
     end
   end
 
@@ -330,6 +319,21 @@ private
     unanswered_partner_questions.each { |i| self["relat#{i}"] = "X" }
   end
 
+  def reset_partner_fields!
+    person_count = hhmemb || 8
+    (2..person_count).each do |i|
+      if send("relat#{i}_changed?") && send("relat#{i}_was") == "P"
+        ((i + 1)..person_count).each do |j|
+          if self["relat#{j}"] == "X"
+            self["relat#{j}"] = nil
+          end
+        end
+      else
+        next
+      end
+    end
+  end
+
   def household_type
     return unless totelder && totadult && totchild