public static String elasticsearchEvent(String indexName, String eventId) {
        checkArgument("indexName", indexName);
        checkArgument("eventId", eventId);

        return String.join(":", ES_EVENT, indexName, eventId);
    }
@Test
    public void elasticsearchEvent() {
        assertThat(EventOriginContext.elasticsearchEvent("gl-events_0", "01DF13GB094MT6390TYQB2Q73Q"))
                .isEqualTo("urn:graylog:event:es:gl-events_0:01DF13GB094MT6390TYQB2Q73Q");

        assertThatCode(() -> EventOriginContext.elasticsearchEvent("", "01DF13GB094MT6390TYQB2Q73Q"))
                .hasMessageContaining("indexName")
                .isInstanceOf(IllegalArgumentException.class);
        assertThatCode(() -> EventOriginContext.elasticsearchEvent(null, "01DF13GB094MT6390TYQB2Q73Q"))
                .hasMessageContaining("indexName")
                .isInstanceOf(IllegalArgumentException.class);

        assertThatCode(() -> EventOriginContext.elasticsearchEvent("gl-events_0", ""))
                .hasMessageContaining("eventId")
                .isInstanceOf(IllegalArgumentException.class);
        assertThatCode(() -> EventOriginContext.elasticsearchEvent("gl-events_0", null))
                .hasMessageContaining("eventId")
                .isInstanceOf(IllegalArgumentException.class);
    }