docs: private void append(final byte[] next_qualifier, final byte[] next_value) {
      ensureCapacity(next_qualifier, next_value);
  
      // Now let's simply concatenate all the values together.
      System.arraycopy(next_value, 0, batched_value, value_index, next_value.length);
      value_index += next_value.length;
  
      // Now let's concatenate all the qualifiers together.
      System.arraycopy(next_qualifier, 0, batched_qualifier, qualifier_index, 
          next_qualifier.length);
      qualifier_index += next_qualifier.length;
    }