src/main/java/org/efaps/ui/wicket/request/EFapsRequestParametersAdapter.java
@Override
    public List<StringValue> getParameterValues(final String _name)
    {
        final List<StringValue> values = this.parameters.get(_name);
        return values != null ? Collections.unmodifiableList(values) : null;
    }
@Override
    public List<StringValue> getParameterValues(final String _name)
    {
        final List<StringValue> values = this.parameters.get(_name);
        return values != null ? Collections.unmodifiableList(values) : null;
    }
Returns list of values for parameter with specified name. If the parameter does not exist
this method returns <code>null</code>

@param _name parameter name
@return list of all values for given parameter or <code>null</code> if parameter does not
exist