code: private void checkField(String fieldName) {
      JavaClass javaClass = checkClass();
      if (javaClass == null) {
        return;
      }
  
      for (JavaClass current = javaClass; current != null; current = getSuperclass(current)) {
        for (Field field : current.getFields()) {
          if (fieldName.equals(field.getName())) {
            // field has been found - check if it's beta
            if (isBeta(field.getAnnotationEntries())) {
              bugReporter.reportBug(createBugInstance(BETA_FIELD_USAGE).addReferencedField(this));
            }
            return;
          }
        }
      }
      bugReporter.logError("Can't locate field " + javaClass.getClassName() + "." + fieldName);
    }
docs: Reports bug in case the field defined by the given name is {@link Beta}.
  
  <p>The field is searched in current class and all super classses as well.