obs.is('something', () => {
console.log('fire!')
})
obs.set('something')
obs.is('something', (data, stamp, target) => {
console.log('fire!')
})
obs.is('something').then(() => {
console.log('fire')
})
obs.is('something').then((target, data, stamp) => {
console.log('fire', target, data, stamp)
})
obs.is((val, data, stamp, target) => val === 'hello')
.then((target, data, stamp) => {
console.log('fire', target, data, stamp)
})