import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.codelibs.core.exception.ClIllegalStateException;
import org.codelibs.core.exception.NoSuchAlgorithmRuntimeException;

/**
 * Utility for handling {@link MessageDigest}.
 *
 * @author higa
 * @author shinsuke
 */

import java.io.IOException;
import java.net.URL;
import java.util.Enumeration;
import java.util.Iterator;

import org.codelibs.core.collection.EnumerationIterator;
import org.codelibs.core.exception.ClIllegalStateException;
import org.codelibs.core.exception.ClassNotFoundRuntimeException;
import org.codelibs.core.exception.IORuntimeException;
import org.codelibs.core.message.MessageFormatter;

/**

     * @param description
     *            The description of why the state is invalid.
     * @throws ClIllegalStateException
     *             If {@code expression} is false.
     */
    public static void assertState(final boolean expression, final String description) {
        if (!expression) {
            throw new ClIllegalStateException(description);
        }
    }

    /**
     * Asserts that the index is not invalid.