public virtual void TestCenterXY()
 {
     com.epl.geometry.Envelope env = new com.epl.geometry.Envelope(-130, 30, -70, 50);
     NUnit.Framework.Assert.AreEqual(-100, env.GetCenterX(), 0);
     NUnit.Framework.Assert.AreEqual(40, env.GetCenterY(), 0);
 }