public JsonPreviewProvider(JsonDatasourceDefinition definition) {
        this.expression = definition.getJsonPathExpressions().getPreview();
 }

JcrPreviewProvider(JcrDatasourceDefinition datasourceDefinition, Provider<HttpServletRequest> requestProvider, LinkProvider linkProvider) {
        this.contextPath = requestProvider.get().getContextPath();
        this.preview = datasourceDefinition.getPreview();
        this.linkProvider = linkProvider;
    }