### Question:
ProcessingContext { public String generateHeadingId(int headingLevel, String headingText) { return idGenerator.newId("h" + headingLevel, headingText); } ProcessingContext(InlineParser inlineParser, ImmutableMap<String, NamedUriWithTitle> links,
			IdGenerator idGenerator); static ProcessingContextBuilder builder(); boolean isEmpty(); NamedUriWithTitle namedUriWithTitle(String name); String generateHeadingId(int headingLevel, String headingText); InlineParser getInlineParser();  }### Answer:
@Test public void generateHeadingId() { ProcessingContext processingContext = ProcessingContext.builder().build(); assertEquals("a", processingContext.generateHeadingId(1, "a")); assertEquals("a2", processingContext.generateHeadingId(1, "a")); assertEquals("a3", processingContext.generateHeadingId(2, "a")); assertEquals("h1-3", processingContext.generateHeadingId(1, null)); assertEquals("h1-4", processingContext.generateHeadingId(1, "")); }