Fix coverage

Author: gdalle

test/printing.jl

@@ -3,4 +3,5 @@ using TestItems
 @testitem "Settings" begin
     @test startswith(string(OperatorRepresentation()), "Operator")
     @test startswith(string(IterativeLinearSolver(; atol=1e-5)), "Iterative")
+    @test startswith(string(IterativeLinearSolver()), "Iterative")
 end