public void AddBranchOnlyOnce()
{
Distribution myDistribution = new Distribution();
Branch myBranch = new Branch();
myDistribution.AddBranch(myBranch);
myDistribution.AddBranch(myBranch);
Assert.IsTrue(myDistribution.Branches.Contains(myBranch));
Assert.AreEqual(1, myDistribution.Branches.Count);
}