# README
contextx：使用后缀 x 表示扩展或变体，简洁且易于记忆。
# Functions
FromAccessToken extract accessToken from context.
FromContext extract auth info from context.
FromUserID extract userID from context.
FromUserM extract *UserM from extract.
NewAccessToken put accessToken into context.
NewContext put auth info into context.
NewUserID put userID into context.
NewUserM put *UserM into context.