code: public void deleteKey(String key) throws IOException {
          Path keyDir = getKeyDir(key);
          HdfsBlobStoreFile pf = new HdfsBlobStoreFile(keyDir, BLOBSTORE_DATA,
                  _hadoopConf);
          pf.delete();
          delete(keyDir);
      }
docs: Delete a key from the blob store
  
  @param key the key to delete
  @throws IOException on any error