docs: public static Class getCallingClass(int matchLevel, Collection<String> extraIgnoredPackages) {
          Class[] classContext = HELPER.getClassContext();
  
          int depth = 0;
          try {
              Class c;
              // this super class stuff is for Java 1.4 support only
              // it isn't needed on a 5.0 VM
              Class sc;
              do {
                  do {
                      c = classContext[depth++];
                      if (c != null) {
                          sc = c.getSuperclass();
                      } else {
                          sc = null;
                      }
                  } while (classShouldBeIgnored(c, extraIgnoredPackages)
                          || superClassShouldBeIgnored(sc));
              } while (c != null && matchLevel-- > 0 && depth<classContext.length);
              return c;
          } catch (Throwable t) {
              return null;
          }
      }