@Override
    public boolean equals(Object o) {
        if ( ! (o instanceof ChunkExpression other)) return false;
        if ( ! other.chunker.equals(this.chunker)) return false;
        return true;
    }
The destination the chunks will be written to on the form [schema name].[field name]
indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ChunkExpression.java