### Question:
BasicTag implements Tag { @Override public String toString() { return key + '=' + value; } BasicTag(String key, String value); @Override String key(); @Override String value(); @Override boolean equals(Object obj); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void testToString() { BasicTag tag = new BasicTag("k1", "v1"); Assertions.assertEquals("k1=v1", tag.toString()); }