remove no-op method

Author: Alexey Stukalov

src/observed/covariance.jl

@@ -76,7 +76,8 @@ function SemObservedCovariance(;
 
     if !isnothing(spec_colnames)
         obs_cov = reorder_obs_cov(obs_cov, spec_colnames, obs_colnames)
-        obs_mean = reorder_obs_mean(obs_mean, spec_colnames, obs_colnames)
+        isnothing(obs_mean) ||
+            (obs_mean = reorder_obs_mean(obs_mean, spec_colnames, obs_colnames))
     end
 
     n_man = Float64(size(obs_cov, 1))
@@ -114,7 +115,6 @@ function reorder_obs_cov(obs_cov, spec_colnames, obs_colnames)
 end
 
 # reorder means ----------------------------------------------------------------------------
-reorder_obs_mean(obs_mean::Nothing, spec_colnames, obs_colnames) = nothing
 
 function reorder_obs_mean(obs_mean, spec_colnames, obs_colnames)
     if spec_colnames == obs_colnames