'A response \'contains\' a string if it is present in the body
of the response.  Whitespace is normalized when searching
for a string.'

def __contains__(self, s):

    if (not isinstance(s, (six.binary_type, six.text_type))):
        s = str(s)
    if isinstance(s, six.text_type):
        s = s.encode('utf8')
    return ((self.body.find(s) != (-1)) or (self.normal_body.find(s) != (-1)))
