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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_auth_basic(self):
 """return the username and password of a basic auth header if it exists"""

        username = ''
        password = ''
        auth_header = self.get_header('authorization')
        if auth_header:
            m = re.search(r"^Basic\s+(\S+)$", auth_header, re.I)
            if m:
                auth_str = Base64.decode(m.group(1))
                username, password = auth_str.split(':', 1)

        return username, password