private void doProcess(final ProcessChoice processChoice) {
        choosePipeline(docRef -> {
            if (docRef != null) {
                confirmSelection("process", () -> {
                    final Selection<Long> selection = getSelection();
                    final ExpressionOperator expression = selectionToExpression(this.criteria, selection);
                    validateExpression(expression, exp -> {
                        final FindMetaCriteria criteria = expressionToNonPagedCriteria(exp);
                        showSummary(
                                criteria,
                                DocumentPermission.VIEW,
                                "processed",
                                "process",
                                "Confirm Process",
                                false,
                                () -> process(docRef, criteria, processChoice));
                    });
                });
            }
        });
    }
@param onSetExpression Called after the expression has been successfully
                       validated and set on the criteria. Can be null.
stroom-core-client/src/main/java/stroom/data/client/presenter/AbstractMetaListPresenter.java