public static void isTrue(boolean expression, String message) {
        if (!expression) {
            throw new IllegalArgumentException(message);
        }
    }
Assert a boolean expression, throwing <code>IllegalArgumentException</code>
if the test result is <code>false</code>.
<pre class="code">Assert.isTrue(i &gt; 0, "The value must be greater than zero");</pre>
@param expression a boolean expression
@param message the exception message to use if the assertion fails
@throws IllegalArgumentException if expression is <code>false</code>
src/main/java/org/apache/shiro/lang/util/Assert.java