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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 http_basic(r, username, password):
 """Attaches HTTP Basic Authentication to the given Request object. Arguments should be considered non-positional. """

    username = str(username)
    password = str(password)

    auth_s = b64encode('%s:%s' % (username, password))
    r.headers['Authorization'] = ('Basic %s' % auth_s)

    return r