FileStatus#setSnapShotEnabledFlag throws InvocationTargetException when attribute set (attr) is Collections.emptySet().
This happens when a FileStatus object is created with none of the four attributes flags (ACL, Encrypted, EC, Snapshot Enabled) and then FileStatus#setSnapShotEnabledFlag is called.
Rationale for not adding additional tests: The exception is easily reproducible by running existing HttpFS test case TestHttpFSWithHttpFSFileSystem#testOperation (ENCRYPTION). The test passes after the patch is applied.
Note that FileStatus#setSnapShotEnabledFlag is already gone in trunk (by