config-prettyfaces/src/main/java/com/ocpsoft/pretty/faces/url/QueryString.java
public <T extends RequestParameter> void addParameters(final List<T> params)
   {
      for (RequestParameter rp : params)
      {
         String value = rp.getValue();
         String name = rp.getName();

         if (!parameters.containsKey(name))
         {
            ArrayList<String> values = new ArrayList<String>();
            if (value != null)
            {
               values.add(value);
            }
            parameters.put(name, values);
         }
         else
         {
            parameters.get(name).add(value);
         }
      }
   }
public <T extends RequestParameter> void addParameters(final List<T> params)
   {
      for (RequestParameter rp : params)
      {
         String value = rp.getValue();
         String name = rp.getName();

         if (!parameters.containsKey(name))
         {
            ArrayList<String> values = new ArrayList<String>();
            if (value != null)
            {
               values.add(value);
            }
            parameters.put(name, values);
         }
         else
         {
            parameters.get(name).add(value);
         }
      }
   }
Add query parameters from the given list of {@link RequestParameter} objects. If a parameter already exists,
append new values to the existing list of values for that parameter.