# Return true if `self` and `other` are the same instance (i.e. same identity).
	#
	# ~~~
	# var a = new Buffer
	# var b = a
	# var c = new Buffer
	# assert a.is_same_instance(b)
	# assert not a.is_same_instance(c)
	# assert a == c # because both buffers are empty
	# ~~~
	#
	# Obviously, the identity of an object is preserved even if the object is mutated.
	#
	# ~~~
	# var x = [1]
	# var y = x
	# x.add 2
	# assert x.is_same_instance(y)
	# ~~~
	#
	# Unless specific code, you should use `==` instead of `is_same_instance` because
	# most of the time is it the semantic (and user-defined) comparison that make sense.
	#
	# Moreover, relying on `is_same_instance` on objects you do not control
	# might have unexpected effects when libraries reuse objects or intern them.
	fun is_same_instance(other: nullable Object): Bool is intern