def replace(msg, special_content):
    return '\n'

def add_call(content, special_info):
    return (special_info, {})

function = {
    'replace': replace,
    'add_call': add_call
}

def replace(msg, special_content):
    return '\n'

def add_call(content, special_info):
    return ({}, special_info)

function = {
    'replace': replace,
    'add_call': add_call
}

Fix bug with 'linebreak' tag