Test Driven Development is a technique in which the refactoring occurs all the time, in the application code and in the test code. But there is not a method to guarantee that the test code behavior after one refactoring remains unchanged. This paper presents a representation based on the JUnit unit test structure, as well as a classification of test code refactorings that may ease the analysis to verify if he test code refactoring was carried out safely, i.e., if the observable behavior of the refactored test code has been kept unchanged. The use of this proposed technique may safely improve and speed up the production of test code refactorings.