pub fn get_self(&mut self) -> Option<&mut ZendObject> {
        // TODO(david): This should be a `&mut self` function but we need to fix arg
        // parser first.
        self.This.object_mut()
    }
Attempts to retrieve the 'this' object, which can be used in class
methods to retrieve the underlying Zend object.

# Example

```no_run
use ext_php_rs::{types::Zval, zend::ExecuteData};

#[no_mangle]
pub extern "C" fn example_fn(ex: &mut ExecuteData, retval: &mut Zval) {
let this = ex.get_self();
dbg!(this);
}
```
src/zend/ex.rs