private void assertCopiedFileIsValid(File expectedFile, File actualFile) throws IOException {
    assertNotNull(actualFile);
    assertTrue(actualFile.exists());
    assertTrue(actualFile.canRead());
    assertTrue(actualFile.isFile());
    assertEquals(expectedFile.length(), actualFile.length());
    assertFilesEqual(expectedFile, actualFile);
  }
Asserts that the copied file is valid.
Checks -
1. File is not null
2. File exists
3. File is readable
4. File is a file
5. File length matches the expected length
6. File contents match the expected file contents
@param expectedFile the expected file.
@param actualFile the actual file.
ambry-file-transfer/src/test/java/com/github/ambry/filetransfer/handler/StoreFileCopyHandlerIntegTest.java