lib/index.esm.js
function (COLLECTION) {
  _export(_export.S, COLLECTION, { of: function of() {
    var length = arguments.length;
    var A = new Array(length);
    while (length--) A[length] = arguments[length];
    return new this(A);
  } });
}
function (COLLECTION) {
  _export(_export.S, COLLECTION, { of: function of() {
    var length = arguments.length;
    var A = new Array(length);
    while (length--) A[length] = arguments[length];
    return new this(A);
  } });
}
function ( COLLECTION ) { _export ( _export . S , COLLECTION , { of : function of ( ) { var length = arguments . length ; var A = new Array ( length ) ; while ( length -- ) A [ length ] = arguments [ length ] ; return new this ( A ) ; } } ) ; }
https://tc39.github.io/proposal-setmap-offrom/
https : // tc39 . github . io / proposal - setmap - offrom /