What is the set method?

const set = new Set();

set.add(1);
set.add(2);
set.add(2);

1
2

const numbers = [1, 1, 2, 2, 3];

const unique =
  [...new Set(numbers)];

[1, 2, 3]

set.add()
set.has()
set.delete()
set.size