Don't require the `--structure` argument.
{
public:
    
    virtual void train(const IColumn & column) = 0;
    
    virtual void finalize() = 0;
    
    virtual ColumnPtr generate(const IColumn & column) = 0;
    
    virtual void updateSeed() = 0;
    
    virtual void serialize(WriteBuffer & out) const = 0;
    
    virtual void deserialize(ReadBuffer & in) = 0;
    virtual ~IModel() = default;
};
using ModelPtr = std::unique_ptr<IModel>;
template <typename... Ts>
UInt64 hash(Ts... xs)
{
    SipHash hash;
    (hash.update(xs), ...);
    return hash.get64();
}
static UInt64 maskBits(UInt64 x, size_t num_bits)
{
    return x & ((1ULL << num_bits) - 1);
}
static UInt64 feistelRound(UInt64 x, size_t num_bits, UInt64 seed, size_t round)