'Assert that the response contains all of the strings passed
in as arguments.
Equivalent to::
assert string in res'

def mustcontain(self, *strings, **kw):

    if ('no' in kw):
        no = kw['no']
        del kw['no']
        if isinstance(no, (six.binary_type, six.text_type)):
            no = [no]
    else:
        no = []
    if kw:
        raise TypeError("The    only    keyword    argument    allowed    is    'no'")
    for s in strings:
        if (not (s in self)):
            print(('Actual    response    (no    %r):' % s), file=sys.stderr)
            print(self, file=sys.stderr)
            raise IndexError(('Body    does    not    contain    string    %r' % s))
    for no_s in no:
        if (no_s in self):
            print(('Actual    response    (has    %r)' % no_s), file=sys.stderr)
            print(self, file=sys.stderr)
            raise IndexError(('Body    contains    string    %r' % s))
