hamt.js
function isLeaf(node) {
    return node === empty || node.type === LEAF || node.type === COLLISION;
}
function isLeaf(node) {
    return node === empty || node.type === LEAF || node.type === COLLISION;
}
function isLeaf ( node ) { return node === empty || node . type === LEAF || node . type === COLLISION ; }
Is `node` a leaf node?
Is node a leaf node?