function TestPlan.visualize(o)local T={}o:visitAllNodes(function(o,u)table.insert(T,(" "):rep(3*u)..o.phrase)end)return table.concat(T,"\n")end
--[[
	Visualizes the test plan in a simple format, suitable for debugging the test
	plan's structure.
]]
function TestPlan:visualize()
	local buffer = {}
	self:visitAllNodes(function(node, level)
		table.insert(buffer, (" "):rep(3 * level) .. node.phrase)
	end)
	return table.concat(buffer, "\n")
end
