import time

pub struct Payload {
	iss ?string    // issuer; usually the domain name of the application issuing the token
	sub ?string    // subject; usually the id of the user the token represents
	aud ?string    // audience; usually the domain name of the application that will receive the token
	exp ?time.Time // expiration time; unix timestamp
	iat ?time.Time // not before; unix timestamp
	ext ?string    // extra data
}

_ := Payload{
	sub: '1234567890'
	exp: time.parse('2019-01-01 00:00:00')
}