@Test
public void findsFilesUnderPrefix() {

    MockManifest a = new MockManifest();
    a.writeFile("foo/bar/a", "hello");
    a.writeFile("foo/bar/b", "hello");
    a.writeFile("foo/bam/qux", "hello");
    assertThat(a.getFilesIn("foo"), contains(
            Paths.get("/foo/bam/qux"), Paths.get("/foo/bar/a"), Paths.get("/foo/bar/b")));
    assertThat(a.getFilesIn("foo/bam"), contains(Paths.get("/foo/bam/qux")));
    assertThat(a.getFilesIn("foo/bar"), contains(Paths.get("/foo/bar/a"), Paths.get("/foo/bar/b")));
    assertThat(a.getFilesIn("foo/bam"), contains(Paths.get("/foo/bam/qux")));
}