### Question:
DirectoryClassPathRoot implements ClasspathRoot { public InputStream getData(final ElementName classname) throws IOException { return getResource(classname.asJavaName().replace('.', File.separatorChar).concat(".class")); } DirectoryClassPathRoot(final File root); InputStream getData(final ElementName classname); InputStream getResource(final String name); Collection<ElementName> classNames();  }### Answer:
@Test public void getDataShouldReturnNullForUnknownClass() throws Exception { this.testee = new DirectoryClassPathRoot(new File("foo")); assertThat(this.testee.getData(ElementName.fromString("bar"))).isNull(); }