How do you access the contents of a JRBeanCollectionDataSource parameter in Jaspersoft Studio?

Hi, I'm passing a parameter of type JRBeanCollectionDataSource from Java to a jasper report like this:

def dataSourcePortfolio = new JRBeanCollectionDataSource(portfolio);
parameters.put("portfolio", dataSourcePortfolio);

Where portfolio is a List of user defined class. I'm already receiving the parameter in the Jaspersoft Studio but I have no idea how to access it. How would I display all contents of the List inside the JRBeanCollectionDataSource? I hope you can help, thanks.