code: @Nonnull
      public static <T> T verifyNotNull(T object, @Nonnull String message) {
          if (object == null) {
              throw new IllegalStateException(message);
          }
          return object;
      }
docs: Check that the argument is not null; if the argument is null, throw an
  IllegalStateException. This method is meant to be used to verify
  conditions on member variables rather than input parameters.
  
  @param object
  reference to check
  @param message
  message to use for the error
  @param <T>
  reference type
  @return the input reference if not null
  @throws IllegalStateException
  if object is null