What do you mean by "append using the driver's capabilities"?

[stratboy]

Hi, in your source code I find this comment:

      Laravel's local disk implementation is quite inefficient for appending data to existing files
      To be at least a bit more efficient, we build the final content ourselves, but the most efficient
      Way to do this would be to append using the driver's capabilities

But what exactly do you mean? Could you show an example? I'm using AS3, thus the League\Flysystem\AwsS3V3\AwsS3V3Adapter, but it doesn't feature any 'append' method or the like.

Thank you