I was wondering what is the join function used in History code sample:
var nanostate = require('nanostate')
var machine = nanostate('cash', {
cash: { check: 'check' },
check: { cash: 'cash' }
})
machine.join('next', nanostate('review', {
review: { previous: '$history' }
}))
What exactly is next and what it changes in machine object?