code: public DataStore createDataStore(Collection<String> columns) {
          DataStore b = new DataStore(columns);
          trackDataStore(b);
  
          return b;
      }
docs: Creates a DataStore with a given set of columns, and tracks it so that any data added will be
  sent on a subsequent send calls.
  
  @param columns Columns in the DataStore
  @return DataStore for storing data for a given set of columns.