add 3d quiver test example

src/examples.jl

@@ -1081,6 +1081,27 @@ const _examples = PlotExample[
             plot!(sin, -π, π, lw=3, color=:red)
         end]
     ),
+    PlotExample(
+        "3d quiver",
+        "",
+        [quote
+            using Plots
+
+            ϕs = range(-π, π, length=50)
+            θs = range(0, π, length=25)
+            θqs = range(1, π-1, length=25)
+            
+            x = vec([sin(θ) * cos(ϕ) for (ϕ, θ) in Iterators.product(ϕs, θs)])
+            y = vec([sin(θ) * sin(ϕ) for (ϕ, θ) in Iterators.product(ϕs, θs)])
+            z = vec([cos(θ) for (ϕ, θ) in Iterators.product(ϕs, θs)])
+            
+            u = 0.1 * vec([sin(θ) * cos(ϕ) for (ϕ, θ) in Iterators.product(ϕs, θqs)])
+            v = 0.1 * vec([sin(θ) * sin(ϕ) for (ϕ, θ) in Iterators.product(ϕs, θqs)])
+            w = 0.1 * vec([cos(θ) for (ϕ, θ) in Iterators.product(ϕs, θqs)])
+            
+            quiver(x,y,z, quiver=(u,v,w))
+        end]
+    )
 ]
 
 # Some constants for PlotDocs and PlotReferenceImages
@@ -1099,6 +1120,7 @@ _backend_skips = Dict(
         32, # spy
         49, # polar heatmap
         51, # image with custom axes
+        52, # 3d quiver
     ],
 )