### Question:
S3InitiateMultipartUploadRequest extends OMKeyRequest { @Override public OMRequest preExecute(OzoneManager ozoneManager) throws IOException { MultipartInfoInitiateRequest multipartInfoInitiateRequest = getOmRequest().getInitiateMultiPartUploadRequest(); Preconditions.checkNotNull(multipartInfoInitiateRequest); KeyArgs keyArgs = multipartInfoInitiateRequest.getKeyArgs(); KeyArgs.Builder newKeyArgs = keyArgs.toBuilder() .setMultipartUploadID(UUID.randomUUID().toString() + "-" + UniqueId.next()).setModificationTime(Time.now()) .setKeyName(validateAndNormalizeKey( ozoneManager.getEnableFileSystemPaths(), keyArgs.getKeyName())); return getOmRequest().toBuilder() .setUserInfo(getUserInfo()) .setInitiateMultiPartUploadRequest( multipartInfoInitiateRequest.toBuilder().setKeyArgs(newKeyArgs)) .build(); } S3InitiateMultipartUploadRequest(OMRequest omRequest); @Override OMRequest preExecute(OzoneManager ozoneManager); @Override @SuppressWarnings("methodlength") OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager,
      long transactionLogIndex,
      OzoneManagerDoubleBufferHelper ozoneManagerDoubleBufferHelper);  }### Answer:
@Test public void testPreExecute() throws Exception { doPreExecuteInitiateMPU(UUID.randomUUID().toString(), UUID.randomUUID().toString(), UUID.randomUUID().toString()); }