powershell fake class sample (not worked)

classutil.ps1

# classutil.ps1
# source from http://mojibake.seesaa.net/article/56484188.html
# class to cls
# var to mem
# def to func

$global:__cls__=@{}

# this function is not worked. why...
function global:cls([string] $name, [ScriptBlock] $definition)
{
    $global:__cls__[$name] = $definition
}

function global:new([string] $typename)
{
    function mem([string] $name, $value = $null){
        $this | Add-Member NoteProperty $name $value
    }
    function func([string] $name, [ScriptBlock] $method) {
        $this | Add-Member ScriptMethod $name $method
    }
    $definition = $global:__cls__[$typename]
    if( !$definition ){
        throw $typename  + " is undefined."
    }
    $obj = New-Object PSObject

    $obj | Add-Member ScriptMethod "__func__" $definition
    $obj.__func__()
    $obj.psobject.members.remove("__func__")

    $obj
}