public void assertMergeTwoReplies(String recipientOne, String recipientTwo) {
        assertSelect(List.of(recipientOne, recipientTwo));

        Map<String, Integer> replies = new HashMap<>();
        replies.put(recipientOne, ErrorCode.NONE);
        replies.put(recipientTwo, ErrorCode.NONE);
        assertMergeOk(replies, List.of(recipientOne, recipientTwo));

        replies.put(recipientOne, ErrorCode.TRANSIENT_ERROR);
        replies.put(recipientTwo, ErrorCode.NONE);
        assertMerge(replies, List.of(ErrorCode.TRANSIENT_ERROR), List.of(recipientOne));

        replies.put(recipientOne, ErrorCode.TRANSIENT_ERROR);
        replies.put(recipientTwo, ErrorCode.FATAL_ERROR);
        assertMerge(replies, List.of(ErrorCode.TRANSIENT_ERROR, ErrorCode.FATAL_ERROR), List.of(recipientTwo));

        replies.put(recipientOne, ErrorCode.TRANSIENT_ERROR);
        replies.put(recipientTwo, ErrorCode.TRANSIENT_ERROR);
        assertMerge(replies, List.of(ErrorCode.TRANSIENT_ERROR, ErrorCode.TRANSIENT_ERROR), List.of(recipientOne, recipientTwo));

        replies.put(recipientOne, ErrorCode.NONE);
        replies.put(recipientTwo, DocumentProtocol.ERROR_MESSAGE_IGNORED);
        assertMergeOk(replies, List.of(recipientOne));

        replies.put(recipientOne, DocumentProtocol.ERROR_MESSAGE_IGNORED);
        replies.put(recipientTwo, ErrorCode.NONE);
        assertMergeOk(replies, List.of(recipientTwo));

        replies.put(recipientOne, DocumentProtocol.ERROR_MESSAGE_IGNORED);
        replies.put(recipientTwo, DocumentProtocol.ERROR_MESSAGE_IGNORED);
        assertMerge(replies, List.of(DocumentProtocol.ERROR_MESSAGE_IGNORED,
                                     DocumentProtocol.ERROR_MESSAGE_IGNORED),
                    null); // Only ignored errors specifically causes an EmptyReply.
    }
Ensures that the current setup will choose the two given recipients, and that it merges similarly to how the
{@link DocumentProtocol} would merge these.

@param recipientOne The first expected recipient.
@param recipientTwo The second expected recipient.
documentapi/src/test/java/com/yahoo/documentapi/messagebus/protocol/test/PolicyTestFrame.java