Can't import static method using MVEL

According to MVEL's documentation, it's possible to import static java methods in a script: http://mvel.codehaus.org/Programmatic+Imports+for+2.0 . The following example is taken from that page, however is not working (I g开发者_Python百科et an Error: unable to access property (null parent): time). What could be wrong?

import java.io.Serializable;
import org.mvel2.MVEL;
import org.mvel2.ParserContext;

public class Test {

    public static void main(String[] args) {

        ParserContext ctx = new ParserContext();
        try {
            ctx.addImport("time", System.class.getMethod("currentTimeMillis", long.class));
        }
        catch (NoSuchMethodException e) {
            // handle exception here.
        }

        Serializable s = MVEL.compileExpression("time();", ctx);
        Object ans = MVEL.executeExpression(s);
        System.out.println(ans.toString());

    }

}

getMethod's second argument used for parameter types, its not used for return type of the method.

change this line:

System.class.getMethod("currentTimeMillis", long.class)

with this:

System.class.getMethod("currentTimeMillis")