assertNullPointerException(() -> vertx.fileSystem().existsSync(null));
assertNullPointerException(() -> vertx.fileSystem().fsProps(null, h -> {}));
assertNullPointerException(() -> vertx.fileSystem().fsPropsSync(null));
String fileName = "some-file.dat";
AsyncFile asyncFile = vertx.fileSystem().openSync(testDir + pathSep + fileName, new OpenOptions());
assertNullPointerException(() -> asyncFile.write(null));
assertIllegalArgumentException(() -> asyncFile.setWriteQueueMaxSize(1));
assertIllegalArgumentException(() -> asyncFile.setWriteQueueMaxSize(0));
assertIllegalArgumentException(() -> asyncFile.setWriteQueueMaxSize(-1));
assertNullPointerException(() -> asyncFile.write(null, 0, h -> {}));
assertNullPointerException(() -> asyncFile.write(Buffer.buffer(), 0, null));
assertIllegalArgumentException(() -> asyncFile.write(Buffer.buffer(), -1, h -> {}));
assertNullPointerException(() -> asyncFile.read(null, 0, 0, 0, h -> {}));
assertNullPointerException(() -> asyncFile.read(Buffer.buffer(), 0, 0, 0, null));
assertIllegalArgumentException(() -> asyncFile.read(Buffer.buffer(), -1, 0, 0, h -> {}));
assertIllegalArgumentException(() -> asyncFile.read(Buffer.buffer(), 0, -1, 0, h -> {}));
assertIllegalArgumentException(() -> asyncFile.read(Buffer.buffer(), 0, 0, -1, h -> {}));
}