### Question:
B2LargeFileStorer { static B2ContentSource createRangedContentSource( B2ContentSource contentSource, long start, long length) throws IOException { final B2ContentSource contentSourceWithRangeOrNull = contentSource.createContentSourceWithRangeOrNull( start, length); if (contentSourceWithRangeOrNull != null) { return contentSourceWithRangeOrNull; } return new B2PartOfContentSource(contentSource, start, length); } B2LargeFileStorer(
            B2FileVersion fileVersion,
            List<B2PartStorer> partStorers,
            B2AccountAuthorizationCache accountAuthCache,
            B2StorageClientWebifier webifier,
            B2Retryer retryer,
            Supplier<B2RetryPolicy> retryPolicySupplier,
            ExecutorService executor); static B2LargeFileStorer forLocalContent(
            B2FileVersion largeFileVersion,
            B2ContentSource contentSource,
            B2PartSizes partSizes,
            B2AccountAuthorizationCache accountAuthCache,
            B2StorageClientWebifier webifier,
            B2Retryer retryer,
            Supplier<B2RetryPolicy> retryPolicySupplier,
            ExecutorService executor);  }### Answer:
@Test public void testCreateRangedContentSource() throws IOException { final B2ContentSource contentSource = new TestContentSource(100, 1000); final B2ContentSource firstRangedContentSource = B2LargeFileStorer.createRangedContentSource( contentSource, 5, 200); assertTrue(firstRangedContentSource instanceof TestContentSource); final B2ContentSource secondRangedContentSource = B2LargeFileStorer.createRangedContentSource( firstRangedContentSource, 10, 50); assertTrue(secondRangedContentSource instanceof B2PartOfContentSource); }