### Question:
JsonObjectBuilderImpl implements JsonObjectBuilder, Serializable { @Override public JsonObjectBuilder addAll(JsonObjectBuilder builder) { attributeMap.putAll(builder.build()); return this; } protected  JsonObjectBuilderImpl();  JsonObjectBuilderImpl(final JsonObject initialData,
                                 final BufferStrategy.BufferProvider<char[]> bufferProvider);  JsonObjectBuilderImpl(final Map<String, Object> initialValues,
                                 final BufferStrategy.BufferProvider<char[]> bufferProvider); void add(final String name, final Object value); @Override JsonObjectBuilder add(final String name, final JsonValue value); @Override JsonObjectBuilder add(final String name, final String value); @Override JsonObjectBuilder add(final String name, final BigInteger value); @Override JsonObjectBuilder add(final String name, final BigDecimal value); @Override JsonObjectBuilder add(final String name, final int value); @Override JsonObjectBuilder add(final String name, final long value); @Override JsonObjectBuilder add(final String name, final double value); @Override JsonObjectBuilder add(final String name, final boolean value); @Override JsonObjectBuilder addNull(final String name); @Override JsonObjectBuilder add(final String name, final JsonObjectBuilder builder); @Override JsonObjectBuilder add(final String name, final JsonArrayBuilder builder); @Override JsonObjectBuilder addAll(JsonObjectBuilder builder); @Override JsonObjectBuilder remove(String name); @Override JsonObject build();  }### Answer:
@Test public void testAddAll() { final JsonObjectBuilder builder = Json.createObjectBuilder(); builder.add("a", "b"); builder.add("c", "d"); final JsonObjectBuilder anotherBuilder = Json.createObjectBuilder(); anotherBuilder.addAll(builder); assertEquals("{\"a\":\"b\",\"c\":\"d\"}", anotherBuilder.build().toString()); }