|  | error[E0599]: no method named `get_a` found for reference `&Self` in the current scope | 
|  | --> $DIR/constrain-trait.rs:16:31 | 
|  | | | 
|  | LL |         println!("{:?}", self.get_a()); | 
|  | |                               ^^^^^ method not found in `&Self` | 
|  | | | 
|  | = help: items from traits can only be used if the type parameter is bounded by the trait | 
|  | help: the following trait defines an item `get_a`, perhaps you need to add another supertrait for it: | 
|  | | | 
|  | LL | trait UseString: std::fmt::Debug + GetString { | 
|  | |                                  +++++++++++ | 
|  |  | 
|  | error[E0599]: no method named `get_a` found for reference `&Self` in the current scope | 
|  | --> $DIR/constrain-trait.rs:22:31 | 
|  | | | 
|  | LL |         println!("{:?}", self.get_a()); | 
|  | |                               ^^^^^ method not found in `&Self` | 
|  | | | 
|  | = help: items from traits can only be used if the type parameter is bounded by the trait | 
|  | help: the following trait defines an item `get_a`, perhaps you need to add a supertrait for it: | 
|  | | | 
|  | LL | trait UseString2: GetString { | 
|  | |                 +++++++++++ | 
|  |  | 
|  | error: aborting due to 2 previous errors | 
|  |  | 
|  | For more information about this error, try `rustc --explain E0599`. |