Enable passing rng to random test

examples/random_systems.jl

@@ -62,30 +62,34 @@ z = CS.tf("z", dt)
 # # Main Test function
 
 # %%
-function test(; nx_p = 2, nx_c = 2, ny = 1, nu = 1, margins = [ 1e-4 ], dt = nothing, use_ss = false, use_parameters = false, sznaier_process = false, sznaier_controller = false, n_margins_reltol = n_margins_reltol, n_margins_abstol = n_margins_abstol, assert_margins = [])
+function test(; nx_p = 2, nx_c = 2, ny = 1, nu = 1, margins = [ 1e-4 ], dt = nothing, use_ss = false, use_parameters = false, sznaier_process = false, sznaier_controller = false, n_margins_reltol = n_margins_reltol, n_margins_abstol = n_margins_abstol, assert_margins = [], rng = nothing)
+
+    if isnothing(rng)
+        rng = default_rng()
+    end
     
     if nx_p == 2 && ny == 1 && nu == 1 && sznaier_process
         A_p = [0.0 1.0; -1.0689391057472464 2.0689391057472464]
         B_p = [0.0; 0.25;;]
         C_p = [-0.1402017127970634 0.13560577241391236]
     else
-        A_p = randn(nx_p, nx_p)
-        B_p = randn(nx_p, nu)
-        C_p = randn(ny, nx_p)
+        A_p = randn(rng, nx_p, nx_p)
+        B_p = randn(rng, nx_p, nu)
+        C_p = randn(rng, ny, nx_p)
     end
 
     if isnothing(nx_c)
-        K_c = randn(nu, ny)    
+        K_c = randn(rng, nu, ny)    
     elseif nx_c == 2 && ny == 1 && nu == 1 && sznaier_controller
         A_c = [-94.67272273545973 -141.87516089498396; 67.09364298153022 101.22237023851974]
         B_c = [876.0675156656737; -548.318385917107;;]
         C_c = [553.6177701648987 879.0336573401709]
         D_c = [201.22797605005874;;]        
     else
-        A_c = randn(nx_c, nx_c)
-        B_c = randn(nx_c, ny)
-        C_c = randn(nu, nx_c)
-        D_c = randn(nu, ny)
+        A_c = randn(rng, nx_c, nx_c)
+        B_c = randn(rng, nx_c, ny)
+        C_c = randn(rng, nu, nx_c)
+        D_c = randn(rng, nu, ny)
     end
 
     if isnothing(nx_c)