async {}
task {}
seq {}
foo {}

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

[
	["computation-expression", "async"], ["punctuation", "{"], ["punctuation", "}"],
	["computation-expression", "task"], ["punctuation", "{"], ["punctuation", "}"],
	["computation-expression", "seq"], ["punctuation", "{"], ["punctuation", "}"],
	["computation-expression", "foo"], ["punctuation", "{"], ["punctuation", "}"]
]

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

Checks for computation expressions.
