in packages/transform/src/visit.js [330:344]
MetaProperty(path) {
let { node } = path;
if (node.meta.name === "function" &&
node.property.name === "sent") {
const t = util.getTypes();
util.replaceWithOrRemove(
path,
t.memberExpression(
t.clone(this.context),
t.identifier("_sent")
)
);
}
}