using groovy to get the cvs's informations from xml folder

I have a folder that have a lot of file .xml which are formatted like below:

<?xml version="1.0" encoding="UTF-8"?>
<psf version="2.0">
    <provider>
        <project reference="1.0,:pserver:cvs.server:/cvs/repo1,project_1,project_1,branche_1"/>
        <project reference="1.0,:pserver:cvs.server:/cvs/repo1,project_1,project_1,branche_2"/>
        <project reference="1.0,:pserver:cvs.server:/cvs/repo2,project_1,project_1,branche_1"/>
        <project reference="1.0,:pserver:cvs.server:/cvs/repo3,project_1,project_1,branche_1"/>
  ...snip...
    </provider>
</psf>

I wrote a groovy scrip to get all the cvs informations so that I can co every project that exists in that files.

import groovy.io.FileType
def list = []
def CVSROOT= []
def PRO=[]
def BRA=[]
new File ('xml/folder').eachFile(FileType.FILES) { file ->
    def psf = new XmlParser().parse(file)
    psf.provider[0].project.each
    {
        list << it.'@reference'.split(/(^1.0|,)/)
    }

The problems is: That is have alot of duplicate cvs informations in per file.(the same CVSROOTs, PROJECTS, BRANCHES).

Any solutions for me. Thanks in advance! I am a newbie in groovy