### Question:
RunInstancesOptions extends BaseEC2RequestOptions { public RunInstancesOptions withClientToken(String clientToken) { formParameters.put("ClientToken", checkNotNull(clientToken, "clientToken")); return this; }  RunInstancesOptions withKeyName(String keyName); RunInstancesOptions withSecurityGroups(String... securityGroups); RunInstancesOptions withSecurityGroups(Iterable<String> securityGroups); RunInstancesOptions withSecurityGroup(String securityGroup); RunInstancesOptions withUserData(byte[] unencodedData); RunInstancesOptions asType(String type); RunInstancesOptions withKernelId(String kernelId); RunInstancesOptions withRamdisk(String ramDiskId); RunInstancesOptions withBlockDeviceMappings(Set<? extends BlockDeviceMapping> mappings); RunInstancesOptions withClientToken(String clientToken); static final RunInstancesOptions NONE; }### Answer:
@Test public void testWithClientToken() { RunInstancesOptions options = withClientToken("some-token"); assertEquals(options.buildFormParameters().get("ClientToken"), ImmutableList.of("some-token")); }
@Test(expectedExceptions = NullPointerException.class) public void testWithClientTokenNPE() { withClientToken(null); }