@Override
  public BaseDataAccessor<ZNRecord> getBaseDataAccessor() {
    throw new UnsupportedOperationException("Unsupported in MockHelixDataAccessor");
  }
Get the child values from ZK of the path specified in the key.
@param key The key that specifies the path.
@param throwException Whether to throw exception if the path does not exist.
@return The list of child values.
@param <T>
ambry-clustermap/src/test/java/com/github/ambry/clustermap/MockHelixDataAccessor.java