Strange stacktrace reported by Google Play Console

I'm getting this kind of stacktraces in the crash reports provided by Google Play Console:

  at com.example.ClassA.createInstance (ClassA.java)
  or                     .op1(ClassA.java)
  or                     .op2(ClassA.java)
  or                     .op3 (ClassA.java)
  or                     .op4 (ClassA.java)

Does anybody knows why are "or"(s) in the stacktrace? I'm guessing is something about the code obfuscation.

Thanks.