Method flush

crates/vm/src/stdlib/_io.rs:2045–2050

(&self, vm: &VirtualMachine)

        #[pymethod]
        fn flush(&self, vm: &VirtualMachine) -> PyResult<()> {
            let mut data = self.writer().lock(vm)?;
            let raw = data.check_init(vm)?;
            ensure_unclosed(raw, "flush of closed file", vm)?;
            data.flush_rewind(vm)
        }
    }

    #[pyattr]