code: public RosettaDF<T> rootMarshal(Marshal<T> marshal) {
  		if(marshal instanceof DocMarshal) {
  			this.marshal = marshal;
  		} else {
  			this.marshal = DocMarshal.root(marshal);
  		}
  		return this;
  	}
docs: Assigning Root Marshal Object
  
  Will wrap with DocMarshal Object if not already
  
  @param marshal
  @return