@Before
  public void setUp() throws IOException {
    Path directory = temporaryFolder.newFolder().toPath();
    Files.createDirectory(directory.resolve("source"));
    Files.createFile(directory.resolve("source/file"));
    Files.createDirectories(directory.resolve("another/source"));
    Files.createFile(directory.resolve("another/source/file"));

    layerBlob1 = Blobs.from("layerBlob1");
    layerDigest1 = digestOf(compress(layerBlob1));
    layerDiffId1 = digestOf(layerBlob1);
    layerSize1 = sizeOf(compress(layerBlob1));
    layerEntries1 =
        ImmutableList.of(
            defaultLayerEntry(
                directory.resolve("source/file"), AbsoluteUnixPath.get("/extraction/path")),
            defaultLayerEntry(
                directory.resolve("another/source/file"),
                AbsoluteUnixPath.get("/another/extraction/path")));

    layerBlob2 = Blobs.from("layerBlob2");
    layerDigest2 = digestOf(compress(layerBlob2));
    layerDiffId2 = digestOf(layerBlob2);
    layerSize2 = sizeOf(compress(layerBlob2));
    layerEntries2 = ImmutableList.of();
  }
Gets the size of {@code blob}.

@param blob the {@link Blob}
@return the size (in bytes) of {@code blob}
@throws IOException if an I/O exception occurs
jib-core/src/test/java/com/google/cloud/tools/jib/cache/CacheTest.java