pub trait BarDescArg {
// Required method
fn as_bar_desc(&self) -> Vec<BarDesc>;
// Provided method
fn as_single_bar_desc(&self) -> BarDesc { ... }
}pub trait BarDescArg {
// Required method
fn as_bar_desc(&self) -> Vec<BarDesc>;
// Provided method
fn as_single_bar_desc(&self) -> BarDesc { ... }
}