@Test
    public void testMetricKeyWithBlankTagKey() {
        MetricName metricName = new MetricName("name", "group", "description",
            Collections.singletonMap("", "value1"));
        MetricKey metricKey = metricNamingStrategy.metricKey(metricName);

        assertEquals("org.apache.kafka.group.name", metricKey.name());
        assertEquals(Collections.singletonMap("", "value1"), metricKey.tags());
    }
Test metric key with mixed name and mixed tags where mixed represents combination of upper case,
lower case, numbers, hyphen, dot, underscore and special characters.
clients/src/test/java/org/apache/kafka/common/telemetry/internals/TelemetryMetricNamingConventionTest.java