diff --git a/Packages/Arrangement/test/Arrangement_2_Traits/include/Circles_traits_test_base.h b/Packages/Arrangement/test/Arrangement_2_Traits/include/Circles_traits_test_base.h
new file mode 100644
index 00000000000..6270784ea93
--- /dev/null
+++ b/Packages/Arrangement/test/Arrangement_2_Traits/include/Circles_traits_test_base.h
@@ -0,0 +1,102 @@
+#include <iostream>
+#include <string>
+
+// Base class for all arrangement traits test classes
+// Class is virtual. Define build_curve_list in your derivative.
+template <class arr_traits>
+class Arr_traits_test {
+
+public:
+  typedef arr_traits              Traits;
+  typedef typename Traits::Curve  Curve;
+
+protected:
+  Traits tr;
+
+  // a data structure to store test info connected with each curve
+  struct Curve_with_info {
+    Curve         cv;
+    bool          is_x_monotone;
+    unsigned      x_monotone_num;
+    std::string   description;
+    
+    // Construction
+    Curve_with_info() {};
+    
+    Curve_with_info(Curve cv_in, bool is_x, int parts, std::string desc) :
+      cv(cv_in), is_x_monotone(is_x), x_monotone_num(parts), 
+      description(desc)
+    {};
+  };
+ 
+  // Builds list of curves, depends on template parameter arr_traits
+  virtual void build_curve_list(std::list<Curve_with_info>& curve_list) = 0;
+
+  // Checks is_x_monotone and make_x_monotone
+  bool check_monotony_functions(std::list<Curve_with_info> curves_list, 
+				bool flip)
+  {
+    bool test_success = true,
+      is_x_monotone;
+    Curve_with_info cv_w_info;
+    std::list<Curve> x_monotone_parts;
+
+    typename std::list<Curve_with_info>::iterator cit = curves_list.begin();
+    for (;
+	 cit != curves_list.end();
+	 cit++) {
+      if (flip) 
+	cit->cv = tr.curve_flip(cit->cv);
+      std::cout << cit->description.c_str();
+      if (flip)
+	std::cout << " flipped";
+      std::cout << std::endl;
+    
+      is_x_monotone = tr.is_x_monotone(cit->cv);
+      if (is_x_monotone != cit->is_x_monotone) {
+	std::cout << "  Should ";
+	std::cout << ((cit->is_x_monotone) ? "be " : "not be ");
+	std::cout << "x-monotone but traits tells the opposite." << std::endl;
+
+	test_success = false;
+      }
+
+      if ( ! is_x_monotone ) {
+	x_monotone_parts.clear();
+	tr.make_x_monotone(cit->cv, x_monotone_parts);
+      
+	if (x_monotone_parts.size() != cit->x_monotone_num) {
+	  std::cout << "  cut into wrong number of parts." << std::endl;
+	  test_success = false;
+	}
+      }
+    } // for
+
+    return test_success;
+  }	       
+
+public:
+
+  // main test routine
+  bool start() 
+  {
+    bool result = true;
+
+    std::list<Curve_with_info> curves_list;
+    
+    build_curve_list(curves_list);
+
+    std::cout << "Checking is_x_monotone and make_x_monotone" << std::endl;
+    std::cout << "------------------------------------------" << std::endl;
+    if ( ! check_monotony_functions(curves_list, false) ) // don't flip
+      result = false;
+    if ( !  check_monotony_functions(curves_list, true) )  // flip curves
+      result = false;
+     
+    // if ( ! check_bla_function(this, that) )
+    //  result = false;
+
+    return result; 
+  }
+
+}; // Arr_traits_test