in src/utils/ChildMapping.js [121:132]
exit: getProp(child, 'exit', nextProps),
enter: getProp(child, 'enter', nextProps),
});
} else if (!hasNext && hasPrev && !isLeaving) {
// item is old (exiting)
// console.log('leaving', key)
children[key] = cloneElement(child, { in: false });
} else if (hasNext && hasPrev && isValidElement(prevChild)) {
// item hasn't changed transition states
// copy over the last transition props;
// console.log('unchanged', key)
children[key] = cloneElement(child, {