code: public static UnsafeSliceFactory getInstance()
      {
          // see setAccessible() in AccessibleObject
          SecurityManager sm = System.getSecurityManager();
          if (sm != null) {
              sm.checkPermission(ACCESS_PERMISSION);
          }
          return INSTANCE;
      }
docs: Get a factory for creating "unsafe" slices that can reference
  arbitrary memory addresses. If there is a security manager, its
  {@code checkPermission} method is called with a
  {@code ReflectPermission("suppressAccessChecks")} permission.
  
  @return an unsafe slice factory