code: public JSONObject copyIndex(String srcIndexName, String dstIndexName) throws AlgoliaException {
      return operationOnIndex("copy", srcIndexName, dstIndexName, null, RequestOptions.empty);
    }
docs: Copy an existing index.
  
  @param srcIndexName the name of index to copy.
  @param dstIndexName the new index name that will contains a copy of srcIndexName (destination will be overriten if it already exist).