Matrix of Symbolic Matrices

[hiiroo]

I have attempted to this;

using Symbolics
@variables X[1:2, 1:2] Y[1:2, 1:2] Z[1:2, 1:2]
test = Array{Symbolics.Arr{Num,2}}(undef, 2,2)
test[:].=[X, Y, Z, X]
sum(test,dims=2)

and I got this;

MethodError: no method matching similar(::Symbolics.Arr{Num, 2}, ::Type{Num}, ::Tuple{UnitRange{Int64}, UnitRange{Int64}})
Closest candidates are:
  similar(::Base.Broadcast.Broadcasted{Base.Broadcast.DefaultArrayStyle{N}}, ::Type{ElType}, ::Any) where {N, ElType} at broadcast.jl:212
  similar(::Base.Broadcast.Broadcasted{Base.Broadcast.ArrayConflict}, ::Type{ElType}, ::Any) where ElType at broadcast.jl:217
  similar(::AbstractArray, ::Type{T}, ::Union{Integer, AbstractUnitRange}...) where T at abstractarray.jl:797
  ...

Stacktrace:
  [1] similar(a::Symbolics.Arr{Num, 2}, #unused#::Type{Num})
    @ Base ./abstractarray.jl:794
  [2] zero(x::Symbolics.Arr{Num, 2})
    @ Base ./abstractarray.jl:1156
  [3] _reducedim_init(f::typeof(identity), op::typeof(Base.add_sum), fv::typeof(zero), fop::typeof(sum), A::Matrix{Symbolics.Arr{Num, 2}}, region::Int64)
    @ Base ./reducedim.jl:120
  [4] reducedim_init(f::Function, op::typeof(Base.add_sum), A::Matrix{Symbolics.Arr{Num, 2}}, region::Int64)
    @ Base ./reducedim.jl:108
  [5] _mapreduce_dim(f::Function, op::Function, #unused#::Base._InitialValue, A::Matrix{Symbolics.Arr{Num, 2}}, dims::Int64)
    @ Base ./reducedim.jl:371
  [6] #mapreduce#765
    @ ./reducedim.jl:357 [inlined]
  [7] #_sum#799
    @ ./reducedim.jl:1023 [inlined]
  [8] _sum
    @ ./reducedim.jl:1023 [inlined]
  [9] #_sum#798
...
    @ In[17]:1
 [13] eval
    @ ./boot.jl:368 [inlined]
 [14] include_string(mapexpr::typeof(REPL.softscope), mod::Module, code::String, filename::String)
    @ Base ./loading.jl:1428

I believe issue tied to the Issue #707. I don't know if there is a proper way of doing it.

Thanks in advance