Provides the function to sleep the system.
It is a class that is statically included in the Cooker.
An instance returned by variable declaration has been initialized.
Returns a singleton instance in response to an instance creation request. That is, variables of this class refer to the same instance.
Returns a new instance of sleep class.
Returns the value that indicates whether this instance was initialized.
Returns the type name.
This class does not have a setter.
Waits during the specified time with freeze.