class JsonResolver extends BasePlugin implements Resolver {

    @Override
    public void initialize(RequestContext requestContext) {
        super.initialize(requestContext);
        oneFieldList = new ArrayList<>();
        mapper = new ObjectMapper();

        // Precompute the column metadata. The metadata is used for mapping column names to json nodes.
        columnDescriptorCache = new ColumnDescriptorCache[requestContext.getColumns()];
        for (int i = 0; i < requestContext.getColumns(); ++i) {
            ColumnDescriptor cd = requestContext.getColumn(i);
            columnDescriptorCache[i] = new ColumnDescriptorCache(cd);
        }
    }

}