def METHOD_NAME(pack,subdir,file_types):
    src_base = os.environ.get('CMSSW_RELEASE_BASE')
    pack_path = os.path.join(src_base,"src",pack,subdir)
    if not os.path.exists(pack_path): return []
    ret_val=[]
    for root, dirs, files in os.walk(pack_path, topdown=False):
        for name in files:
            for t in file_types:
                if name.endswith(t):
                    ret_val.append(os.path.join(root,name))
    return ret_val