interface BaggageInterface

interface BaggageInterface extends ImplicitContextKeyedInterface {
    
    /**
     * Returns the {@see API\BaggageInterface} from the provided *$context*,
     * falling back on {@see API\BaggageInterface::getEmpty()} if there is no baggage in the provided context.
     */
    public static function fromContext(ContextInterface $context) : API\BaggageInterface;
    
    /**
     * Returns a new empty {@see API\BaggageBuilderInterface}.
     */
    public static function getBuilder() : API\BaggageBuilderInterface;
    
    /**
     * Returns the current {@see Baggage} from the current {@see ContextInterface},
     * falling back on {@see API\BaggageInterface::getEmpty()} if there is no baggage in the current context.
     */
    public static function getCurrent() : API\BaggageInterface;
    
    /**
     * Returns a new {@see API\BaggageInterface} with no entries.
     */
    public static function getEmpty() : API\BaggageInterface;
    
    /**
     * @see https://github.com/open-telemetry/opentelemetry-specification/blob/v1.6.1/specification/baggage/api.md#get-value
     */
    public function getEntry(string $key) : ?API\Entry;
    
    /**
     * Returns the value from the {@see API\Entry} with the provided *key*.
     * @see getEntry
     *
     * @return mixed
     */
    public function getValue(string $key);
    
    /**
     * @see https://github.com/open-telemetry/opentelemetry-specification/blob/v1.6.1/specification/baggage/api.md#get-all-values
     */
    public function getAll() : iterable;
    public function isEmpty() : bool;
    
    /**
     * Returns a new {@see API\BaggageBuilderInterface} pre-initialized with the contents of `$this`.
     */
    public function toBuilder() : API\BaggageBuilderInterface;

}