Options for Fs.createWriteStream.
Fs.createWriteStream
@:optionaloptionalstart:Null<Int>
position to write data the beginning of the file.
@:optionaloptionalmode:Null<FsMode>
default: 0666
@:optionaloptionalflags:Null<FsOpenFlag>
default: 'w'
@:optionaloptionalencoding:Null<String>
default: null