data = (
{
  class = "mpdf_harness";
  mpdf = {
    class = "mprod";
    mpdfs = ( 
    {
      class = "mgamma";
      beta = 2.0;
      k = 1.0;
      rv : 
      {
	class = "RV";
	names = ( "b" );
      };
      rvc : 
      {
	class = "RV";
	names = ( "a" );
      };
    }, 
    {
      class = "mepdf";
      epdf : 
      {
	class = "egamma";
	alpha = 2.0;
	beta = 2.0;
	rv : 
	{
	  class = "RV";
	  names = ( "a" );
	};
      };
    });
  };
  mean = [ 1.0, 1.0 ];
  R = ( "matrix", 2, 2, [ 2.0, 0.5, 0.5, 0.5 ] );
  variance = [ 1.2, 5.0 ];
  tolerance = 0.2;
});