Desing Interface of Labin Probetas

Today i continue work on the Proyect. Cardoce suggested investigate about the TDD and JUnit. TDD or Test-drive development its a methodology to use before the create a proyect or function, with this i need follow a series of steps. JUnit is a library that helps to inplement the TDD in my code. Also in this day i begin to create the interface, i think the fasest and easiest form to create it is with designer of NetBeans. On this day i complete the interface but i want see the opinion of Raquel, them the rest of the day read clean code chapter 6 but i can´t finish. On this chapter talk about the Objects and structures and how  i can represents