{
  "category": "JavaScript",
  "flag_name": "--js-flags=--js_upsert",
  "id": 5201653661827072,
  "milestone": 145,
  "name": "Upsert",
  "summary": "ECMAScript proposal for Map.prototype.getOrInsert, Map.prototype.getOrInsertComputed, WeakMap.prototype.getOrInsert, and WeakMap.prototype.getOrInsertComputed."
}

{
  "category": "JavaScript",
  "flag_name": null,
  "id": 5193275975794688,
  "milestone": 146,
  "name": "Iterator Sequencing",
  "summary": "A TC39 proposal to create iterators by sequencing existing iterators. Introduces Iterator.concat ( ...items )."
}

{
  "category": "JavaScript",
  "flag_name": null,
  "id": 4790090146643968,
  "milestone": 147,
  "name": "Math.sumPrecise",
  "summary": "A TC39 proposal to add a method to sum multiple values to JavaScript.\n\nAdd an iterable-taking `Math.sumPrecise` method which returns the sum of the values in the iterable using a more precise algorithm than naive summation."
}