reintroduce code cov for counting single prox access.

test/plans/test_proximal_plan.jl

@@ -15,9 +15,11 @@ include("../utils/dummy_types.jl")
     M = Euclidean(2)
     p = [1.0, 2.0]
     Q = [[2.0, 3.0], [3.0, 4.0]]
-    f(M, p) = sum(distance(M, p, q) for q in Q)
+    f(M, p) = 0.5 * sum(distance(M, p, q)^2 for q in Q)
+    f2(M, p) = 0.5 * distance(M, p, Q[1])
     proxes_f = Tuple((N, λ, p) -> prox_distance(N, λ, q, p) for q in Q)
     ppo = ManifoldProximalMapObjective(f, proxes_f)
+    ppo2 = ManifoldProximalMapObjective(f2, proxes_f[1])
     @testset "Objective Decorator passthrough" begin
         dppo = DummyDecoratedObjective(ppo)
         for i in 1:2
@@ -44,6 +46,14 @@ include("../utils/dummy_types.jl")
         get_proximal_map!(M, q2, cppo2, 0.1, p, 1)
         @test q2 == q
         @test get_count(cppo2, :ProximalMap) == 2
+        # single function
+        cppo3 = ManifoldCountObjective(M, ppo2, Dict([:ProximalMap => 0]))
+        q = get_proximal_map(M, cppo3, 0.1, p)
+        @test q == get_proximal_map(M, ppo2, 0.1, p)
+        q2 = copy(M, p)
+        get_proximal_map!(M, q2, cppo3, 0.1, p)
+        @test q2 == q
+        @test get_count(cppo3, :ProximalMap) == 2
     end
     @testset "Cache" begin
         cppo = ManifoldCountObjective(M, ppo, [:ProximalMap])