Background returns a non-nil, empty Context.

LegFromContext extracts `Leg` from context and returns `nil` when no instance of `Leg` can be found.

LegWithContext injects `Leg` to context.

NewTransitWithContext injects a new `Transit` to context.

Shipment returns the shipment associated with this context for key, or nil if no value is associated with key.

ShipmentRange calls f sequentially for each shipment in the context stack.

TODO returns a non-nil, empty Context.

TransitFromContext extracts `Transit` from context and returns `nil` when no instance of `Transit` can be found.

TransitWithContext injects `Transit` to context.

WithCancel returns a copy of parent with a new Done channel.

WithDeadline returns a copy of the parent context with the deadline adjusted to be no later than d.

WithLogger returns a copy of parent with a contextualised `log.Logger`.

WithShipment returns a copy of parent in which the value associated with key is val.

WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)).

WithTracer returns a copy of parent with a contextualised `log.Tracer`.

WithValue returns a copy of parent in which the value associated with key is val.

Canceled is the error returned by Context.Err when the context is canceled.

DeadlineExceeded is the error returned by Context.Err when the context's deadline passes.

ErrInvalidTransitBinary occurs when UnmarshalBinary is called on Transit with an invalid binary representation.

ErrInvalidTransitText occurs when UnmarshalText is called on Transit with an invalid textual representation.

TransitFactory creates empty Transit instances.

A Leg is a point-to-point request bounded by a process.

A Transit is request context that goes beyond a process.

A Context carries a deadline, a cancelation signal, and other values across API boundaries.