@gmf(foo="bar")
@namespace(uri="testmodel", prefix="testmodel")
package testmodel;

@gmf.diagram(onefile="true")
class Mainclass {
  val NodeTypeOne[*] NodeTypeOneNodes;
  val NodeTypeTwo[*] NodeTypeTwoNodes;
}

@gmf.node(figure="rectangle",label="identifier")
class NodeTypeOne{
  attr String identifier;
  @gmf.link(target.decoration="filledclosedarrow", color="0,0,0")
  ref NodeTypeOne[*] NodeTypeOneRefsOfOne;
  @gmf.link(target.decoration="filledclosedarrow", color="0,0,0")
  ref NodeTypeTwo[*] NodeTypeTwoRefsOfOne;
}

@gmf.node(figure="rectangle",label="identifier")
class NodeTypeTwo{
  attr String identifier;
  @gmf.link(target.decoration="filledclosedarrow", color="0,0,0")
  ref NodeTypeOne[*] NodeTypeOneRefsOfTwo;
}