Fix method visibility in inline diff class

lib/gitlab/diff/inline_diff.rb

@@ -19,24 +19,6 @@ module Gitlab
 
       attr_accessor :old_line, :new_line, :offset
 
-      def self.for_lines(lines)
-        changed_line_pairs = self.find_changed_line_pairs(lines)
-
-        inline_diffs = []
-
-        changed_line_pairs.each do |old_index, new_index|
-          old_line = lines[old_index]
-          new_line = lines[new_index]
-
-          old_diffs, new_diffs = new(old_line, new_line, offset: 1).inline_diffs
-
-          inline_diffs[old_index] = old_diffs
-          inline_diffs[new_index] = new_diffs
-        end
-
-        inline_diffs
-      end
-
       def initialize(old_line, new_line, offset: 0)
         @old_line = old_line[offset..-1]
         @new_line = new_line[offset..-1]
@@ -63,10 +45,29 @@ module Gitlab
         [old_diffs, new_diffs]
       end
 
+      class << self
+        def for_lines(lines)
+          changed_line_pairs = find_changed_line_pairs(lines)
+
+          inline_diffs = []
+
+          changed_line_pairs.each do |old_index, new_index|
+            old_line = lines[old_index]
+            new_line = lines[new_index]
+
+            old_diffs, new_diffs = new(old_line, new_line, offset: 1).inline_diffs
+
+            inline_diffs[old_index] = old_diffs
+            inline_diffs[new_index] = new_diffs
+          end
+
+          inline_diffs
+        end
+
         private
 
         # Finds pairs of old/new line pairs that represent the same line that changed
-      def self.find_changed_line_pairs(lines)
+        def find_changed_line_pairs(lines)
           # Prefixes of all diff lines, indicating their types
           # For example: `" - +  -+  ---+++ --+  -++"`
           line_prefixes = lines.each_with_object("") { |line, s| s << line[0] }.gsub(/[^ +-]/, ' ')
@@ -88,6 +89,9 @@ module Gitlab
 
           changed_line_pairs
         end
+      end
+
+      private
 
       def longest_common_prefix(a, b)
         max_length = [a.length, b.length].max