def METHOD_NAME():
    """Simple non-convex model with many local minima"""
    model = ConcreteModel()
    model.x1 = Var(initialize=1, bounds=(0, 100))
    model.x2 = Var(initialize=5, bounds=(5, 6))
    model.x2.fix(5)
    model.objtv = Objective(expr=model.x1 * sin(model.x1), sense=maximize)
    return model