我正在尝试BeautifulSoup文档中的一个例子，但发现它表现得很奇怪。当我尝试访问next_sibling值时，除了"body"之外，还出现了'\n'。
html_doc = """
<html><head><title>The Dormouse's story</title></head>
<body>
<p class="title"><b>The Dormouse's story</b></p>
<p class="story">Once upon a time there were three little sisters; and their names were
<a href="http://example.com/elsie" class="sister" id="link1">Elsie</a>,
<a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and
<a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>;
and they lived at the bottom of a well.</p>
<p class="story">...</p>
"""
from bs4 import BeautifulSoup
soup = BeautifulSoup(html_doc)
soup.head.next_sibling
u'\n'
我正在使用最新版本的beautifulSoup4，即4.3.2。请帮助我解决问题。提前致谢。