""
"fo""o"
"foo
bar"
''
'fo''o'
'foo
bar'

----------------------------------------------------

[
	["string", "\"\""],
	["string", "\"fo\"\"o\""],
	["string", "\"foo\r\nbar\""],
	["string", "''"],
	["string", "'fo''o'"],
	["string", "'foo\r\nbar'"]
]

----------------------------------------------------

Checks for single-quoted and double-quoted strings.