public static String elasticsearchMessage(String indexName, String messageId) {
        checkArgument("indexName", indexName);
        checkArgument("messageId", messageId);

        return String.join(":", ES_MESSAGE, indexName, messageId);
    }
@Test
    public void elasticsearchMessage() {
        assertThat(EventOriginContext.elasticsearchMessage("graylog_0", "b5e53442-12bb-4374-90ed-c325c0d979ce"))
                .isEqualTo("urn:graylog:message:es:graylog_0:b5e53442-12bb-4374-90ed-c325c0d979ce");

        assertThatCode(() -> EventOriginContext.elasticsearchMessage("", "b5e53442-12bb-4374-90ed-c325c0d979ce"))
                .hasMessageContaining("indexName")
                .isInstanceOf(IllegalArgumentException.class);
        assertThatCode(() -> EventOriginContext.elasticsearchMessage(null, "b5e53442-12bb-4374-90ed-c325c0d979ce"))
                .hasMessageContaining("indexName")
                .isInstanceOf(IllegalArgumentException.class);

        assertThatCode(() -> EventOriginContext.elasticsearchMessage("graylog_0", ""))
                .hasMessageContaining("messageId")
                .isInstanceOf(IllegalArgumentException.class);
        assertThatCode(() -> EventOriginContext.elasticsearchMessage("graylog_0", null))
                .hasMessageContaining("messageId")
                .isInstanceOf(IllegalArgumentException.class);
    }