//! another function. It suffices to just take a reference in order to introduce
//! an edge. Consider the following example:
//!
-//! ```rust
+//! ```
+//! # use core::fmt::Display;
//! fn print_val<T: Display>(x: T) {
//! println!("{}", x);
//! }
//!
-//! fn call_fn(f: &Fn(i32), x: i32) {
+//! fn call_fn(f: &dyn Fn(i32), x: i32) {
//! f(x);
//! }
//!