pub trait PartitionKeysOption<'a> {
// Required method
fn partition_keys(&self) -> Option<&'a PartitionKeys>;
// Provided method
fn add_header(&self, builder: Builder) -> Builder { ... }
}
pub trait PartitionKeysOption<'a> {
// Required method
fn partition_keys(&self) -> Option<&'a PartitionKeys>;
// Provided method
fn add_header(&self, builder: Builder) -> Builder { ... }
}