@Override
      public ReplicaId getReplicaId() {
        MockClusterMap mockClusterMap = null;
        try {
          mockClusterMap = new MockClusterMap(false, true, 1,
              10, 3, false,
              false, null);
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
        MockPartitionId partitionId = new MockPartitionId(1L, mockClusterMap.DEFAULT_PARTITION_CLASS,
            mockClusterMap.getDataNodes(), 0);
        return partitionId.getReplicaIds().get(0);
      }
Tests when fileCopyHandler is failed and onFileCopyFailure is called.
and onFileCopySuccess is not called
ambry-file-transfer/src/test/java/com/github/ambry/filetransfer/FileCopyThreadTest.java