// 2. Let n be the fileName argument to the constructor.
// NOTE: Underlying OS filesystems use differing conventions for file name; with constructed files, mandating UTF-16 lessens ambiquity when file names are converted to byte sequences.
// 3. Process FilePropertyBag dictionary argument by running the following substeps:
if(options.has_value()){
// 1. If the type member is provided and is not the empty string, let t be set to the type dictionary member.
// If t contains any characters outside the range U+0020 to U+007E, then set t to the empty string and return from these substeps.
// NOTE: t is set to empty string at declaration.
if(!options->type.is_empty()){
if(is_basic_latin(options->type))
type=options->type;
}
// 2. Convert every character in t to ASCII lowercase.
if(!type.is_empty())
type=options->type.to_lowercase();
// 3. If the lastModified member is provided, let d be set to the lastModified dictionary member. If it is not provided, set d to the current date and time represented as the number of milliseconds since the Unix Epoch (which is the equivalent of Date.now() [ECMA-262]).
// Note: Since ECMA-262 Date objects convert to long long values representing the number of milliseconds since the Unix Epoch, the lastModified member could be a Date object [ECMA-262].