title: Formset object has no attribute 'absolute_max'
body: <p>I want to create bills in my app. I have one extra_bill_form and multible item_forms.</p>
  
  <p>view:</p>
  
  <pre><code>def ExtraBillView(request):
      item_form_set = formset_factory(ItemForm, formset=BaseItemFormSet, can_delete=True)
      extra_bill_form = ExtraBillForm()
  
      if request.method == 'POST':
          item_form_set = BaseItemFormSet(request.POST)
          extra_bill_form = ExtraBillForm(request.POST)
  
          if extra_bill_form.is_valid() and item_form_set.is_valid():
              al1 = extra_bill_form.cleaned_data.get('adress_line1')
              al2 = extra_bill_form.cleaned_data.get('adress_line2')
              al3 = extra_bill_form.cleaned_data.get('adress_line3')
              al4 = extra_bill_form.cleaned_data.get('adress_line4')
  
              for form in item_form_set:
                  pass
          pdb.set_trace()
  
          else:
              extra_bill_form = ExtraBillForm()
              item_form_set = formset_factory(ItemForm, formset=BaseItemFormSet, extra=0, max_num=5, min_num=1)
  
      context = {
          'extra_bill_form': extra_bill_form,
          'item_form_set': item_form_set,
      }
  
      return render(request, 'extra_bill.html', context)
  </code></pre>
  
  <p>form:</p>
  
  <pre><code>class ExtraBillForm(forms.Form):
      adress_line1 = forms.CharField(label='Adresszeile 1:', required=True)
      adress_line2 = forms.CharField(label='Adresszeile 2:', required=False)
      adress_line3 = forms.CharField(label='Adresszeile 3:', required=False)
      adress_line4 = forms.CharField(label='Adresszeile 4:', required=False)
  
  
  class ItemForm(forms.Form):
      name = forms.CharField(label='Artikelname:')
      ust = forms.IntegerField(label='UST:', initial=20)
      price_nto = forms.IntegerField(label='Preis netto:', required=False)
      price_brt = forms.IntegerField(label='Preis brutto:', required=False)
  
  
  class BaseItemFormSet(BaseFormSet):
      def clean(self):
          if self.price_nto is None:
              if self.price_brt is None:
                  return
          if any(self.errors):
              return
  </code></pre>
  
  <p>If I submitt my forms, I get an error:</p>
  
  <blockquote>
    <p>'BaseItemFormSet' object has no attribute 'absolute_max'
    how to solve this problem?</p>
  </blockquote>
  
  <pre><code>Environment:
  Request Method: POST
  Request URL: http://127.0.0.1:8000/calculator/extrabill/
  
  Django Version: 1.9.4
  Python Version: 3.5.1
  Installed Applications:
  ['django.contrib.admin',
   'django.contrib.auth',
   'django.contrib.contenttypes',
   'django.contrib.sessions',
   'django.contrib.messages',
   'django.contrib.staticfiles',
   'django_ajax',
   'django_bootstrap_dynamic_formsets',
   'Bank',
   'bootstrap3',
   'Building',
   'Calculator',
   'CounterChange',
   'Customer',
   'Credit',
   'Hackgut',
   'Heatingplant',
   'Index',
   'jquery',
   'jquery_ui',
   'Measurement',
   'Price',
   'Rate']
  Installed Middleware:
  ['django.middleware.security.SecurityMiddleware',
   'django.contrib.sessions.middleware.SessionMiddleware',
   'django.middleware.common.CommonMiddleware',
   'django.middleware.csrf.CsrfViewMiddleware',
   'django.contrib.auth.middleware.AuthenticationMiddleware',
   'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
   'django.contrib.messages.middleware.MessageMiddleware',
   'django.middleware.clickjacking.XFrameOptionsMiddleware']
  
  Traceback:
  
  File "/usr/lib/python3.5/site-packages/django/core/handlers/base.py" in get_response
    149. response = self.process_exception_by_middleware(e, request)
  
  File "/usr/lib/python3.5/site-packages/django/core/handlers/base.py" in get_response
    147. response = wrapped_callback(request, *callback_args, **callback_kwargs)
  
   File "/home/klaus/PycharmProjects/waerme/Calculator/views.py" in ExtraBillView
    94. if extra_bill_form.is_valid() and item_form_set.is_valid():
  
   File "/usr/lib/python3.5/site-packages/django/forms/formsets.py" in is_valid
    316. self.errors
  
   File "/usr/lib/python3.5/site-packages/django/forms/formsets.py" in errors
    290. self.full_clean()
  
  File "/usr/lib/python3.5/site-packages/django/forms/formsets.py" in full_clean
    337. for i in range(0, self.total_form_count()):
  
  File "/usr/lib/python3.5/site-packages/django/forms/formsets.py" in total_form_count
    116. return min(self.management_form.cleaned_data[TOTAL_FORM_COUNT], self.absolute_max)
  
  Exception Type: AttributeError at /calculator/extrabill/
  Exception Value: 'BaseItemFormSet' object has no attribute 'absolute_max'
  </code></pre>