### Question:
DynamicCompositeByteBuf { public boolean isEmpty() { return readableBytes == 0; } DynamicCompositeByteBuf();  DynamicCompositeByteBuf(int capacity);  DynamicCompositeByteBuf(ByteBuf buf);  DynamicCompositeByteBuf(ByteBuf[] bufs, int offset, int len); int readableBytes(); boolean isEmpty(); boolean hasArray(); byte[] array(); int arrayOffset(); int readerIndex(); boolean isReadable(); ByteBuf nettyByteBuf(); void addBuffer(ByteBuf buffer); ByteBuf readRetainedSlice(int length); ByteBuf retainedSlice(int length); void skipBytes(int length); DynamicCompositeByteBuf readBytes(byte[] dst); DynamicCompositeByteBuf readBytes(byte[] dst, int dstIndex, int length); byte readByte(); short readUnsignedByte(); short readShort(); short readShortLE(); int readUnsignedShort(); int readUnsignedShortLE(); int readInt(); int readIntLE(); long readLong(); long readLongLE(); char readChar(); float readFloat(); float readFloatLE(); double readDouble(); double readDoubleLE(); ByteOrder order(); void release(); @Override String toString();  }### Answer:
@Test public void testIsEmpty() { DynamicCompositeByteBuf compositeByteBuf = new DynamicCompositeByteBuf(); Assert.assertTrue(compositeByteBuf.isEmpty() == true); ByteBuf buf1 = Unpooled.wrappedBuffer("hello1".getBytes()); DynamicCompositeByteBuf compositeByteBuf2 = new DynamicCompositeByteBuf(buf1); Assert.assertTrue(compositeByteBuf2.isEmpty() == false); }