Champion Level 3If I understand correctly, it's not possible. If for example, you did have a "global class", how would other projects use or reference this class if it's in another project? Also, how would developers know if there's an existing method? It might be documented, but these days no one reads specs!
My team of developers always discuss if there are any existing methods which they can use to perform a particular task, before creating a new method. But this requires knowledge of the software.
Testers may create a function on the project they are working on, I'll review their code and I will usually point out there's an existing method in the Common project that they can use. Again, this requires knowledge of the software i.e. being test automation framework.
