How to allow mulitple field values for managed metadata column using client object model in sharepoint 2010?

Hello, 

I have one managed metadata column which has terms like c#, asp.net, php. so i want to set all the term values to a single document. There is a facility provided as "Allow Multiple Values" in List settings. so I have to make such facility "Allow Multiple Values" of terms programmatically using client object model (C#) in Sharepoint 2010.