public void testStringConcatenation() {
    // debugging MVEL code, it seems that MVEL 'thinks' that the result of the expression:
    // "Drop +5%: "+$sb+" avg: $"+$av+" price: $"+$pr
    // is a double, and as so, he looks for a method:
    // Services.log( double );
    // but finds only:
    // Services.log( String );
    // raising the error.
    String ex = "services.log((String) \"Drop +5%: \"+$sb+\" avg: $\"+$av+\" price: $\"+$pr );";
    ParserContext ctx = new ParserContext();
    ctx.setStrongTyping(true);
    ctx.addInput("$sb",
        String.class);
    ctx.addInput("$av",
        double.class);
    ctx.addInput("$pr",
        double.class);
    ctx.addInput("services",
        Services.class);
    try {
      ExpressionCompiler compiler = new ExpressionCompiler(ex, ctx);
      compiler.compile();
    }
    catch (Throwable e) {
      e.printStackTrace();
      fail("Should not raise exception: " + e.getMessage());
    }
  }