class Async::Container::Generic

def spawn(name: nil, restart: false, key: nil, health_check_timeout: nil, &block)

@parameter health_check_timeout [Numeric | Nil] The maximum time a child instance can run without updating its state, before it is terminated as unhealthy.
@parameter key [Symbol] A key used for reloading child instances.
@parameter restart [Boolean] Whether to restart the child instance if it fails.
@parameter name [String] The name of the child instance.
Spawn a child instance into the container. 
def spawn(name: nil, restart: false, key: nil, health_check_timeout: nil, &block)
	name ||= UNNAMED
	
	if mark?(key)
		Console.debug(self) {"Reusing existing child for #{key}: #{name}"}
		return false
	end
	
	@statistics.spawn!
	
	fiber do
		while @running
			child = self.start(name, &block)
			
			state = insert(key, child)
			
			# If a health check is specified, we will monitor the child process and terminate it if it does not update its state within the specified time.
			if health_check_timeout
				age_clock = state[:age] = Clock.start
			end
			
			begin
				status = @group.wait_for(child) do |message|
					case message
					when :health_check!
						if health_check_timeout&.<(age_clock.total)
							health_check_failed!(child, age_clock, health_check_timeout)
						end
					else
						state.update(message)
						age_clock&.reset!
					end
				end
			ensure
				delete(key, child)
			end
			
			if status.success?
				Console.debug(self) {"#{child} exited with #{status}"}
			else
				@statistics.failure!
				Console.error(self, status: status)
			end
			
			if restart
				@statistics.restart!
			else
				break
			end
		end
	end.resume
	
	return true
end