public static void state(boolean expression, String message) {
        if (!expression) {
            throw new IllegalStateException(message);
        }
    }
Assert a boolean expression, throwing <code>IllegalStateException</code>
if the test result is <code>false</code>. Call isTrue if you wish to
throw IllegalArgumentException on an assertion failure.
<pre class="code">Assert.state(id == null, "The id property must not already be initialized");</pre>

@param expression a boolean expression
@param message    the exception message to use if the assertion fails
@throws IllegalStateException if expression is <code>false</code>
lang/src/main/java/org/apache/shiro/lang/util/Assert.java