Given arrays with missing values, I am unable to workout the mean of a mutli-dimensional array over a given region

For example,

```
x = convert(Array{Union{Float64,Missing}}, rand(2,2))
x[1] = missing
mean(skipmissing(x))
```

works as expected. However computing the mean over a given region, say `mean(skipmissing(x), 2)`

returns an error indicating that the relevant method has not been defined.

Other than writing my own method (which I cannot do at the moment), is there a way to calculate the mean of a mutli-dimensional array with missing values over a given region?