Create form.

def create_form(self, obj=None):
        """Create form."""
        kbtype = request.args['kbtype'] if 'kbtype' in request.args else 'w'

        if kbtype == KnwKB.KNWKB_TYPES['written_as']:
            self.form = WrittenAsKnowledgeForm
        elif kbtype == KnwKB.KNWKB_TYPES['dynamic']:
            self.form = DynamicKnowledgeForm
        else:
            self.form = TaxonomyKnowledgeForm

        form = self.form()
        form.kbtype.data = kbtype

        return form