### Question:
JjdocProgramInvoker extends AbstractProgramInvoker { @Override public String supportedSuffix() { return SUPPORTED_FILE_SUFFIX; } JjdocProgramInvoker(Project project, Configuration classpath, File tempOutputDirectory); @Override ProgramArguments augmentArguments(File inputDirectory, RelativePath inputRelativePath, ProgramArguments arguments); @Override String getProgramName(); @Override String supportedSuffix(); static final String SUPPORTED_FILE_SUFFIX; }### Answer:
@Test public void supportsJavaccFiles() { String supportedSuffix = programInvoker.supportedSuffix(); assertThat(supportedSuffix, is(equalTo(".jj"))); }