/// Create and schedule a timer that will call `block` once after the specified time.

public class func after(_ interval: TimeInterval, _ block: () -> Void) -> Timer {

let timer = Timer.new(after: interval, block)

timer.start()

/// Create and schedule a timer that will call `block` repeatedly in specified time intervals.

public class func every(_ interval: TimeInterval, _ block: () -> Void) -> Timer {

let timer = Timer.new(every: interval, block)

timer.start()

/// Create and schedule a timer that will call `block` repeatedly in specified time intervals.

/// (This variant also passes the timer instance to the block)

let timer = Timer.new(every: interval, block)

timer.start()

return timer