@Test
public void testGetBondLengthAverage_MultiReaction() {

    IReaction reaction = new Reaction();
    // mol 1
    IAtom atom1 = new Atom("C");
    atom1.setPoint2d(new Point2d(0, 0));
    IAtom atom2 = new Atom("C");
    atom2.setPoint2d(new Point2d(1, 0));
    IAtomContainer acont = new AtomContainer();
    reaction.addReactant(acont);
    acont.addAtom(atom1);
    acont.addAtom(atom2);
    acont.addBond(0, 1, IBond.Order.SINGLE);
    // mol 2
    atom1 = new Atom("C");
    atom1.setPoint2d(new Point2d(0, 0));
    atom2 = new Atom("C");
    atom2.setPoint2d(new Point2d(3, 0));
    acont = new AtomContainer();
    reaction.addProduct(acont);
    acont.addAtom(atom1);
    acont.addAtom(atom2);
    acont.addBond(0, 1, IBond.Order.SINGLE);
    Assert.assertEquals(2.0, GeometryTools.getBondLengthAverage(reaction), 0.0);
}