public BsonMemberMap SetElementName(string elementName)
{
if (elementName == null)
{
throw new ArgumentNullException("elementName");
}
if (elementName.IndexOf('\0') != -1)
{
throw new ArgumentException("Element names cannot contain nulls.", "elementName");
}
if (_frozen) { ThrowFrozenException(); }
_elementName = elementName;
return this;
}