writeStringz

suspend fun AsyncOutputStream.writeStringz(str: String, charset: Charset = UTF8)
suspend fun AsyncOutputStream.writeStringz(str: String, len: Int, charset: Charset = UTF8)
fun SyncOutputStream.writeStringz(str: String, charset: Charset = UTF8)
fun SyncOutputStream.writeStringz(str: String, len: Int, charset: Charset = UTF8)