testCase{gen2, "roses are red, violets are blue...", "red are red, blue are blue..."},
		testCase{gen2, "", ""},
	)

	// gen3 has multiple old strings with an overall common prefix.
	gen3 := NewReplacer(
		"abracadabra", "poof",
		"abracadabrakazam", "splat",
		"abraham", "lincoln",
		"abrasion", "scrape",
		"abraham", "isaac",
	)
	testCases = append(testCases,

NOTE	all standard compliant implementations should pass these : 2002-05-31

BE	abracadabra$	abracadabracadabra	(7,18)
BE	a...b		abababbb		(2,7)
BE	XXXXXX		..XXXXXX		(2,8)
E	\)		()	(1,2)
BE	a]		a]a	(0,2)
B	}		}	(0,1)
E	\}		}	(0,1)
BE	\]		]	(0,1)
B	]		]	(0,1)
E	]		]	(0,1)
B	{		{	(0,1)
B	}		}	(0,1)
BE	^a		ax	(0,1)
BE	\^a		a^a	(1,3)
BE	a\^		a^	(0,2)
BE	a$		aa	(1,2)
BE	a\$		a$	(0,2)
BE	^$		NULL	(0,0)
E	$^		NULL	(0,0)