### Question:
LocalFileSystem extends ChecksumFileSystem { @Override public String getScheme() { return "file"; } LocalFileSystem();  LocalFileSystem(FileSystem rawLocalFileSystem); @Override void initialize(URI name, Configuration conf); @Override String getScheme(); FileSystem getRaw(); File pathToFile(Path path); @Override void copyFromLocalFile(boolean delSrc, Path src, Path dst); @Override void copyToLocalFile(boolean delSrc, Path src, Path dst); boolean reportChecksumFailure(Path p, FSDataInputStream in,
                                       long inPos,
                                       FSDataInputStream sums, long sumsPos);  }### Answer:
@Test public void testStatistics() throws Exception { FileSystem.getLocal(new Configuration()); int fileSchemeCount = 0; for (Statistics stats : FileSystem.getAllStatistics()) { if (stats.getScheme().equals("file")) { fileSchemeCount++; } } assertEquals(1, fileSchemeCount); }