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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_varint(v, f):
 """Encode integer `v` to file `f`. Parameters v: int Integer v >= 0. f: file Object containing a write method. Returns ------- int Number of bytes written. """

    assert v >= 0
    num_bytes = 0

    while True:
        b = v % 0x80
        v = v // 0x80

        if v > 0:
            b = b | 0x80

        f.write(FIELD_U8.pack(b))

        num_bytes += 1
        if v == 0:
            break

    return num_bytes