@Override
    protected void onDeserialize(Deserializer buf) {
        super.onDeserialize(buf);
        int b = buf.getByte(null);
        dim = Dimension.valueOf(b);
    }
Obtain the predefined bucket list of this bucket expression

@return what part of the time you have requested
searchlib/src/main/java/com/yahoo/searchlib/expression/ZCurveFunctionNode.java