I tried:
  const state =  new Set( [5, 10, 15, 20, 30, 45, 60] );
  let preset = Object.assign( {}, state );
  console.log(preset)
  // {}
and got empty object. Also I tried to convert state to string and also failed:
state.values().toLocaleString()
// "[object Set Iterator]"
Or the only way is to iterate Set one by one?
Update: It should be an Array of values: [5, 10, 15, 20, 30, 45, 60] as a result.
 
     
    