'Process the token stream'

def process(self, stack, stream):

    for (token_type, value) in stream:
        is_keyword = (token_type in T.Keyword)
        if is_keyword:
            (yield (T.Text, u'<strong>'))
        (yield (token_type, escape(value)))
        if is_keyword:
            (yield (T.Text, u'</strong>'))
