Imagine that the variables return upon call: list1, list2, list3.

It is difficult to say exactly what will be returned when calling list1, list2, list3 without context. Usually, such names imply lists (arrays or collections). For example, if these are test data:

• list1 might contain a basic set of elements,
• list2 — an extended or filtered list,
• list3 — a union or result of processing the first two.

In QA automation, these could be different sets of test data or results used to verify various scenarios. To give a precise answer, the code or description of the functions returning these variables is needed.