autodoc import error for plugin.rst

Getting following error while running tox

loading pickled environment... done
Using openstack theme from /home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/oslosphinx/theme
building [html]: all source files
updating environment: 0 added, 1 changed, 0 removed
Traceback (most recent call last):
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 326, in import_object
    obj = self.get_attr(obj, part)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 232, in get_attr
    return safe_getattr(obj, name, *defargs)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/util/inspect.py", line 70, in safe_getattr
    raise AttributeError(name)
AttributeError: KEKMetaDTO
Traceback (most recent call last):
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 326, in import_object
    obj = self.get_attr(obj, part)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 232, in get_attr
    return safe_getattr(obj, name, *defargs)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/util/inspect.py", line 70, in safe_getattr
    raise AttributeError(name)
AttributeError: EncryptDTO
Traceback (most recent call last):
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 326, in import_object
    obj = self.get_attr(obj, part)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 232, in get_attr
    return safe_getattr(obj, name, *defargs)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/util/inspect.py", line 70, in safe_getattr
    raise AttributeError(name)
AttributeError: DecryptDTO
Traceback (most recent call last):
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 326, in import_object
    obj = self.get_attr(obj, part)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 232, in get_attr
    return safe_getattr(obj, name, *defargs)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/util/inspect.py", line 70, in safe_getattr
    raise AttributeError(name)
AttributeError: GenerateDTO
Traceback (most recent call last):
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 326, in import_object
    obj = self.get_attr(obj, part)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/ext/autodoc.py", line 232, in get_attr
    return safe_getattr(obj, name, *defargs)
  File "/home/atiwari/cloudDev/barbicanDev/barbican-master/.tox/venv/lib/python2.7/site-packages/sphinx/util/inspect.py", line 70, in safe_getattr
    raise AttributeError(name)
AttributeError: CryptoPluginBase

/home/atiwari/cloudDev/barbicanDev/barbican-master/doc/source/plugin.rst:35: WARNING: autodoc can't import/find class 'barbican.plugin.crypto.KEKMetaDTO', it reported error: "KEKMetaDTO", please check your spelling and sys.path
/home/atiwari/cloudDev/barbicanDev/barbican-master/doc/source/plugin.rst:37: WARNING: autodoc can't import/find class 'barbican.plugin.crypto.EncryptDTO', it reported error: "EncryptDTO", please check your spelling and sys.path
/home/atiwari/cloudDev/barbicanDev/barbican-master/doc/source/plugin.rst:39: WARNING: autodoc can't import/find class 'barbican.plugin.crypto.DecryptDTO', it reported error: "DecryptDTO", please check your spelling and sys.path
/home/atiwari/cloudDev/barbicanDev/barbican-master/doc/source/plugin.rst:41: WARNING: autodoc can't import/find class 'barbican.plugin.crypto.GenerateDTO', it reported error: "GenerateDTO", please check your spelling and sys.path
/home/atiwari/cloudDev/barbicanDev/barbican-master/doc/source/plugin.rst:50: WARNING: autodoc can't import/find class 'barbican.plugin.crypto.CryptoPluginBase', it reported error: "CryptoPluginBase", please check your spelling and sys.path