working TCC (Test response funciton)

app/lib/irt/test_response_function.py

@@ -1,12 +1,17 @@
+from lib.irt.item_response_function import ItemResponseFunction
+
 # otherwise known as the Test Characteristic Curve (TCC)
 class TestResponseFunction():
-  def __init__(self, irf):
-    self.irf = irf
+  def __init__(self, irt_model):
+    self.irt_model = irt_model
+    self.irf = ItemResponseFunction(irt_model)
 
   def calculate(self, items, **kwargs):
-    result = 0
+    sum = 0
 
     for item in items:
-      result += irf.calculate(b_param=item.b_param, theta=kwargs['theta'])
+      result = self.irf.calculate(b_param=item.b_param, theta=kwargs['theta'])
+      item.irf = result
+      sum += item.irf
 
-    return result
+    return sum