public static void isTrue(boolean expression) {
        isTrue(expression, "[Assertion failed] - this expression must be true");
    }
Assert a boolean expression, throwing <code>IllegalArgumentException</code>
if the test result is <code>false</code>.
<pre class="code">Assert.isTrue(i &gt; 0);</pre>

@param expression a boolean expression
@throws IllegalArgumentException if expression is <code>false</code>
lang/src/main/java/org/apache/shiro/lang/util/Assert.java