update rule 4 comment

Co-authored-by: Mythicaeda <[email protected]>

db-tests/src/test/java/gov/nasa/jpl/aerie/database/ExternalEventTests.java

@@ -1302,9 +1302,7 @@ void rule3_empty() throws SQLException {
 
       ////////////////////////// RULE 4 //////////////////////////
       /**
-       * Tests rule 4, where we require that later sources with events bearing the same key as an event in an earlier
-       *    source replace said events. To test this, while not conflating with any other cases tested above, we use
-       *    completely sparse sources, just to purely illustrate rule 4 and that it works.
+       * An event that appears in a later source will replace its occurrence in an earlier source, even if the sources don't overlap.
        *
        *    A:                   ++++aaa+++++
        *    B:                                  +++++aaaaa+