How to get current time in milliseconds in Rust?

Hello everyone! I just started learning Rust and encountered a task that is very simple in other languages, but causes difficulties here. I need to measure the execution time of some code section, and for that I want to get the current time in milliseconds (timestamp since the Unix epoch, January 1, 1970). I wrote this code, but it doesn't compile: ```rust use std::time; fn main() { let now = time::now(); let millis = now.elapsed().as_millis(); println!("Current time in ms: {}", millis); } ``` The compiler complains that `time::now()` doesn't exist, and the `elapsed()` method is not suitable at all. I looked at the documentation, but there are many different structures: `SystemTime`, `Instant`, `Duration` — I'm confused. In Python I would write `time.time() * 1000`, in JavaScript — `Date.now`