That annotation tells PowerMock(ito) that the listed classes will need to be manipulated on the byte code level.
You need to “prepare for test” all these classes X of which you want to
- mock a static method (on X)
- gain control over calls to
new()used in another class X - gain control over private methods (which you do using a spy and
PowerMockito.when(spy, "privateMethodNameAsString").then...
In other words:
- To mock
X.doStatic(), you have to prepare the class X. - To control
new Y(...), you have to prepare the class X that contains thatnewstatement.