LL | println!("Hello", "World");
 | ------- ^^^^^^^ argument never used
 | |
 | formatting specifier missing
 |
 = note: format specifiers use curly braces: `{}`
help: consider adding format specifier
 |
LL | println!("Hello{}", "World");
 | ++

LL | println!("list: {}", 1, 2, 3);
 | ---------- ^ ^ argument never used
 | | |
 | | argument never used
 | multiple missing formatting specifiers
 |
 = help: consider adding 2 format specifiers