IfNoneMatchPreconditionHeader implements PreconditionHeader<EntityTag> { @Override public String getKey() { return IF_NONE_MATCH_HEADER_KEY; } private  IfNoneMatchPreconditionHeader(final EntityTagMatchers entityTagsToMatch); @Override String getKey(); @Override String getValue(); @Override boolean meetsConditionFor(@Nullable final EntityTag entityTag); static Optional<IfNoneMatchPreconditionHeader> fromDittoHeaders(final DittoHeaders dittoHeaders);  }
@Test public void getKey() { final IfNoneMatchPreconditionHeader ifNoneMatchPreconditionHeader = createIfNoneMatchPreconditionHeader(EntityTagMatchers.fromCommaSeparatedString("\"test\"")); assertThat(ifNoneMatchPreconditionHeader.getKey()).isEqualTo("if-none-match"); }