1 files changed, 6 insertions, 3 deletions
diff --git a/extractor/suffix_array.h b/extractor/suffix_array.h
index 7708f5a2..79a22694 100644
--- a/extractor/suffix_array.h
+++ b/extractor/suffix_array.h
@@ -21,17 +21,20 @@ class SuffixArray {
 
   virtual int GetSize() const;
 
-  shared_ptr<DataArray> GetData() const;
+  virtual shared_ptr<DataArray> GetData() const;
 
-  vector<int> BuildLCPArray() const;
+  virtual vector<int> BuildLCPArray() const;
 
-  int GetSuffix(int rank) const;
+  virtual int GetSuffix(int rank) const;
 
   virtual PhraseLocation Lookup(int low, int high, const string& word,
                                 int offset) const;
 
   void WriteBinary(const fs::path& filepath) const;
 
+ protected:
+  SuffixArray();
+
  private:
   void BuildSuffixArray();