a_field_class = self._tc.create_real_field_class()
b_field_class = self._tc.create_signed_integer_field_class(17)
self._append_element_method(self._fc, 'a_float', a_field_class)
a_field_class = self._tc.create_real_field_class()
b_field_class = self._tc.create_signed_integer_field_class(17)
self._append_element_method(self._fc, 'a_float', a_field_class)