'Looks for exact match to \'string\' in history page'

def check_history_for_exact_string(self, string, show_deleted=False):

    if show_deleted:
        self.visit_url('/history?show_deleted=True')
    else:
        self.visit_url('/history')
    try:
        tc.find(string)
    except:
        fname = self.write_temp_file(tc.browser.get_html())
        errmsg = ("no    match    to    '%s'\npage    content    written    to    '%s'" % (string, fname))
        raise AssertionError(errmsg)
