Unity - Scripting API:

public static function Assert(condition: bool): void;

public static function Assert(condition: bool, message: string): void;

public static function Assert(condition: bool, format: string, params args: object[]): void;

Parameters

condition	Condition you expect to be true.
message	String or object to be converted to string representation for display.
format	Formatted string for display.
args	Arguments for the formatted string.

Assert the condition.

Message of a type of LogType.Assert is logged.