<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _compute_permanent_id(private_key):
 """ Internal helper. Return an authenticated service's permanent ID given an RSA private key object. The permanent ID is the base32 encoding of the SHA1 hash of the first 10 bytes (80 bits) of the public key. """

    pub = private_key.public_key()
    p = pub.public_bytes(
        encoding=serialization.Encoding.PEM,
        format=serialization.PublicFormat.PKCS1
    )
    z = ''.join(p.decode('ascii').strip().split('\n')[1:-1])
    b = base64.b64decode(z)
    h1 = hashlib.new('sha1')
    h1.update(b)
    permanent_id = h1.digest()[:10]
    return base64.b32encode(permanent_id).lower().decode('ascii')