'Assert that C{s} starts with a particular C{prefix}.
@param s: The input string.
@type s: C{str}
@param prefix: The string that C{s} should start with.
@type prefix: C{str}'

def assertStartsWith(self, s, prefix):

    self.assertTrue(s.startswith(prefix), ('%r    is    not    the    start    of    %r' % (prefix, s)))
