func Config(r *http.Request, key ...string) (*SessionConfig, error) {
	return DefaultSessionFactory.Config(r, key...)
}
Config returns the configuration for a given session.

The key argument is optional; if not set it'll use the default session key.
package sessions
import (
	"bytes"
	"crypto/aes"
	"crypto/cipher"
	"crypto/hmac"
	"crypto/rand"
	"crypto/subtle"
	"encoding/base64"
	"errors"
	"fmt"
	"gob"
	"hash"
	"http"
	"strconv"
	"time"
	"gorilla.googlecode.com/hg/gorilla/context"
)
func init() {
	gob.Register(SessionData{})
	gob.Register([]interface{}{})
	DefaultSessionFactory.SetStore("cookie", new(CookieSessionStore))
}
var (
	DefaultSessionKey = "s"
	DefaultStoreKey   = "cookie"
	DefaultFlashesKey = "_flash"
	ErrEncoding       = errors.New("The value could not be encoded.")
	ErrDecoding       = errors.New("The value could not be decoded.")
	ErrAuthentication = errors.New("The value could not be verified using HMAC.")
	ErrDecryption     = errors.New("The value could not be decrypted.")
	ErrMaxLength      = errors.New("The value exceeds the maximum allowed length.")
	ErrBadTimestamp   = errors.New("Invalid timestamp.")
	ErrNewTimestamp   = errors.New("The value has a newer timestamp than expected.")
	ErrOldTimestamp   = errors.New("The value has an expired timestamp.")
	ErrMissingHash    = errors.New("A hash is required to create and verify values using HMAC.")
	ErrMissingHashKey = errors.New("Authentication secret can't be nil.")
	ErrNoSession      = errors.New("No session found for the given key.")
	ErrNoFlashes      = errors.New("No flashes found for the given key.")
	ErrNoStore        = errors.New("No store found for the given key.")
	ErrStoreMismatch  = errors.New("A session with the given key already exists using a different store.")
	ErrBadIdLength    = errors.New("Session id length must be greater than zero.")
)
type SessionData map[string]interface{}
type SessionConfig struct {
	Path   string
	Domain string
	MaxAge   int
	Secure   bool
	HttpOnly bool
}
type SessionInfo struct {
	Data   SessionData
	Store  SessionStore
	Config SessionConfig
}
func Session(r *http.Request, vars ...string) (SessionData, error) {
	return DefaultSessionFactory.Session(r, vars...)
}
func Flashes(r *http.Request, vars ...string) ([]interface{}, error) {
	return DefaultSessionFactory.Flashes(r, vars...)
}
func AddFlash(r *http.Request, value interface{},
	vars ...string) (bool, error) {
	return DefaultSessionFactory.AddFlash(r, value, vars...)
}