UndefinedInterfaceName: soap in unit tests

When running the Ladon unit tests (from trunk 112), I got the following error:
[andre:/tmp/trash/branch/ladon/frameworks/python/tests] [branch] ladon(112) 6s ⚯ python testladon.py
127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 178
127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 165
.127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/soap HTTP/1.1" 500 338
F127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 176
127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 163
.127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/soap HTTP/1.1" 500 338
F127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 176
127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 163
.127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/soap HTTP/1.1" 500 338
F127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 174
127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/jsonwsp HTTP/1.1" 200 161
.127.0.0.1 - - [13/Apr/2014 19:44:23] "POST /StringTestService/soap HTTP/1.1" 500 338
F
======================================================================
FAIL: test_bytes_in_bytes_out_soap (__main__.StringTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testladon.py", line 124, in test_bytes_in_bytes_out_soap
    self.string_integrety_tests_soap('bytes_in_bytes_out')
  File "testladon.py", line 99, in string_integrety_tests_soap
    self.assertEqual(status, 200)
AssertionError: 500 != 200

======================================================================
FAIL: test_bytes_in_uni_out_soap (__main__.StringTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testladon.py", line 127, in test_bytes_in_uni_out_soap
    self.string_integrety_tests_soap('bytes_in_uni_out')
  File "testladon.py", line 99, in string_integrety_tests_soap
    self.assertEqual(status, 200)
AssertionError: 500 != 200

======================================================================
FAIL: test_uni_in_bytes_out_soap (__main__.StringTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testladon.py", line 130, in test_uni_in_bytes_out_soap
    self.string_integrety_tests_soap('uni_in_bytes_out')
  File "testladon.py", line 99, in string_integrety_tests_soap
    self.assertEqual(status, 200)
AssertionError: 500 != 200

======================================================================
FAIL: test_uni_in_uni_out_soap (__main__.StringTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "testladon.py", line 133, in test_uni_in_uni_out_soap
    self.string_integrety_tests_soap('uni_in_uni_out')
  File "testladon.py", line 99, in string_integrety_tests_soap
    self.assertEqual(status, 200)
AssertionError: 500 != 200

----------------------------------------------------------------------
Ran 8 tests in 0.212s

FAILED (failures=4)
[andre:/tmp/trash/branch/ladon/frameworks/python/tests] [branch] ladon(112) ⚯

Printing the resdata directly in unit tests, I got the following:
ipdb> print resdata
Traceback (most recent call last):
  File "/tmp/trash/branch/ladon/frameworks/python/tests/ladon/server/wsgi_application.py", line 340, in __call__
    raise UndefinedInterfaceName(ifname,'The interface name "%s" has not been defined' % ifname)
UndefinedInterfaceName:
interface name: soap
The interface name "soap" has not been defined

ipdb>

Investigating a bit further I understood the problem comes from the DocumentLiteralSOAPInterface _interface_name static method, it returns "soapdocumentliteral" rather than "soap".