The test class `KeywordFieldMapperTests` contains a switch statement with a branch that will never execute. The test uses a `between(x, y)` switch expression, but the `4` case is outside the randomised range. We need to fix this before #88739 can be merged. By "fix", I mean either remove the spurious case, or if we actually want it then extend the randomized range.
server/src/test/java/org/elasticsearch/index/mapper/KeywordFieldMapperTests.java
() -> merge(mapperService, fieldMapping(b -> b.field("type", "keyword").field("normalizer", "other_lowercase")))
        );
        assertEquals(
            "Mapper for [field] conflicts with existing mapper:\n"
                + "\tCannot update parameter [normalizer] from [lowercase] to [other_lowercase]",
            e.getMessage()
        );
    }
    public void testSplitQueriesOnWhitespace() throws IOException {
        MapperService mapperService = createMapperService(mapping(b -> {
            b.startObject("field").field("type", "keyword").endObject();
            b.startObject("field_with_normalizer");
            {
                b.field("type", "keyword");
                b.field("normalizer", "lowercase");
                b.field("split_queries_on_whitespace", true);
            }
            b.endObject();
        }));
        MappedFieldType fieldType = mapperService.fieldType("field");
        assertThat(fieldType, instanceOf(KeywordFieldMapper.KeywordFieldType.class));
        KeywordFieldMapper.KeywordFieldType ft = (KeywordFieldMapper.KeywordFieldType) fieldType;
        Analyzer a = ft.getTextSearchInfo().searchAnalyzer();
        assertTokenStreamContents(a.tokenStream("", "Hello World"), new String[] { "Hello World" });
        fieldType = mapperService.fieldType("field_with_normalizer");
        assertThat(fieldType, instanceOf(KeywordFieldMapper.KeywordFieldType.class));
        ft = (KeywordFieldMapper.KeywordFieldType) fieldType;
        assertThat(ft.getTextSearchInfo().searchAnalyzer().name(), equalTo("lowercase"));
        assertTokenStreamContents(
            ft.getTextSearchInfo().searchAnalyzer().analyzer().tokenStream("", "Hello World"),