code: public static void same(Object obj1, Object obj2, RuntimeException cause) {
      if (obj1 != obj2) {
        throw cause;
      }
    }
docs: Asserts that two {@link Object objects} are the same {@link Object} as determined by the identity comparison.
  
  The assertion holds if and only if the two {@link Object objects} are the same {@link Object} in memory.
  
  @param obj1 {@link Object left operand} in the identity comparison.
  @param obj2 {@link Object right operand} in the identity comparison.
  @param cause {@link RuntimeException} thrown if the assertion fails.
  @throws java.lang.RuntimeException if the {@link Object objects} are not the same.
  @see java.lang.Object