The assert statement is a convenient mechanism for incorporating diagnostic tests in code. The behavior of the assert statement depends on the status of a runtime property. When enabled, the assert statement evaluates its expression argument and throws an AssertionError if false. When disabled, assert is defined to be a no-op; any side effects resulting from evaluation of the expression in the assertion are lost when assertions are disabled. Consequently, expressions used with the standard assert statement must not produce side effects.
...