docs: public static Class<?> getCallingClass() {
          ClassContextSecurityManager securityManager = getSecurityManager();
          if (securityManager == null)
              return null;
          Class<?>[] trace = securityManager.getClassContext();
          String thisClassName = Util.class.getName();
  
          // Advance until Util is found
          int i;
          for (i = 0; i < trace.length; i++) {
              if (thisClassName.equals(trace[i].getName()))
                  break;
          }
  
          // trace[i] = Util; trace[i+1] = caller; trace[i+2] = caller's caller
          if (i >= trace.length || i + 2 >= trace.length) {
              throw new IllegalStateException("Failed to find org.slf4j.helpers.Util or its caller in the stack; " + "this should not happen");
          }
  
          return trace[i + 2];
      }