Supported Calls

create(), delete(), getDeleted(), getUpdated(), query(), retrieve(), undelete(), update(), upsert(), describeSObjects()

But this Apex code doesn't compile:  

Save error: DML not allowed on MailmergeTemplate testMoveToMailMerge.cls /i360/src/classes line 12

public class testMoveToMailMerge 
{
public static MailmergeTemplate MoveFile(string FileName, string TemplateName)
{
Document doc = [Select ID, Body, BodyLength, ContentType, FolderID, Name, Description, DeveloperName, NamespacePrefix, Type, Keywords FROM Document WHERE Name = :FileName Limit 1];
System.Debug(doc);
MailmergeTemplate template = new MailmergeTemplate();
template.Name = TemplateName;
template.Body = doc.Body;
template.Description = doc.Description;
template.Filename = doc.Name;		
insert template;
MailmergeTemplate RetTemplate = [Select Name, Id, Filename, Description, BodyLength, Body From MailmergeTemplate WHERE Id = :template.Id];	
return RetTemplate;
}
public static testMethod void TestMove()
{
string FileName = 'TempTestMailMerge1';
string TemplateName = 'Ping Pong';
MailmergeTemplate template = MoveFile(FileName, TemplateName);
Document doc = [Select ID, Body, BodyLength, ContentType, FolderID, Name, Description, DeveloperName, NamespacePrefix, Type, Keywords FROM Document WHERE Name = :FileName Limit 1];
System.AssertEquals(template.Name, TemplateName);
System.AssertEquals(template.BodyLength, doc.BodyLength);
}
}