I'm currently working on a PHP project and I came across the `stream_filter_append()` function. I'm having trouble understanding how to use it and I couldn't find a good example online.
To give you some background, I'm working on a system where I need to filter the data coming in from a stream before processing it further. I heard that `stream_filter_append()` can be useful for this.
Could someone please provide me with an example of how to use the `stream_filter_append()` function in PHP? Specifically, I would like to see how it can be used to filter the data from a stream.
Thanks in advance for your help!