// provided when decrypting an encrypted DEK.
type Context map[string]string

// MarshalText returns a canonical text representation of
// the Context.

// MarshalText sorts the context keys and writes the sorted
// key-value pairs as canonical JSON object. The sort order
// is based on the un-escaped keys. It never returns an error.
func (c Context) MarshalText() ([]byte, error) {
	if len(c) == 0 {
		return []byte{'{', '}'}, nil
	}