internal override void WriteSpatialTypeAttributes(IEdmSpatialTypeReference reference)
 {
     if (reference.IsGeography())
     {
         this.WriteOptionalAttribute(CsdlConstants.Attribute_Srid, reference.SpatialReferenceIdentifier, CsdlConstants.Default_SpatialGeographySrid, SridAsXml);
     }
     else if (reference.IsGeometry())
     {
         this.WriteOptionalAttribute(CsdlConstants.Attribute_Srid, reference.SpatialReferenceIdentifier, CsdlConstants.Default_SpatialGeometrySrid, SridAsXml);
     }
 }