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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 encode(data):
 """encode the plantuml data which may be compresses in the proper encoding for the plantuml server """

    res = ""
    for i in range(0,len(data), 3):
        if (i+2==len(data)):
            res += _encode3bytes(ord(data[i]), ord(data[i+1]), 0)
        elif (i+1==len(data)):
            res += _encode3bytes(ord(data[i]), 0, 0)
        else:
            res += _encode3bytes(ord(data[i]), ord(data[i+1]), ord(data[i+2]))
    return res