The Text class is accessible via the paste.fixture module.
{'button': <class 'paste.fixture.Submit'>,
'checkbox': <class 'paste.fixture.Checkbox'>,
'hidden': <class 'paste.fixture.Hidden'>,
'radio': <class 'paste.fixture.Radio'>,
'select': <class 'paste.fixture.Select'>,
'submit': <class 'paste.fixture.Submit'>,
'text': <class 'paste.fixture.Text'>,
'textarea': <class 'paste.fixture.Textarea'>}
See the source for more information.