Function Once

test/visitor.test.ts:60–62

(i)

      visits.push(['DocumentExit', `${i.nodes.length}`])
    },
    Once(i) {
      visits.push(['Once', `${i.nodes.length}`])
    },
    OnceExit(i) {
      visits.push(['OnceExit', `${i.nodes.length}`])
    },