Remove nillable= true from wsdc in WCF service

See more:

WCF

C#4.0

I have class like

[DataContract]
    public partial class TEST
    {
        [DataMember]
        public string ROLL { get; set; }
        [DataMember]
        public int NUM { get; set; }
        [DataMember(IsRequired=true)]
        public string SNAME { get; set; }
    }

When I see in xsd of wsdl it generate following code.

<pre><xs:element minOccurs="0" name="SNAME" nillable="true" type="xs:string"/>

How I can remove nillable="true" attribute from xsd.

What I have tried:

Looked in google but did not find relevant solution.