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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 _ensure_length(encoded, min_length, alphabet, guards, values_hash):
 """Ensures the minimal hash length"""

    len_guards = len(guards)
    guard_index = (values_hash + ord(encoded[0])) % len_guards
    encoded = guards[guard_index] + encoded

    if len(encoded) < min_length:
        guard_index = (values_hash + ord(encoded[2])) % len_guards
        encoded += guards[guard_index]

    split_at = len(alphabet) // 2
    while len(encoded) < min_length:
        alphabet = _reorder(alphabet, alphabet)
        encoded = alphabet[split_at:] + encoded + alphabet[:split_at]
        excess = len(encoded) - min_length
        if excess > 0:
            from_index = excess // 2
            encoded = encoded[from_index:from_index+min_length]

    return encoded