LinearAlgebra/addmul/mul!(::Matrix{BigFloat}, ::LinearAlgebra.Bidiagonal{Float64, V} where V<:AbstractVector{Float64}, ::LinearAlgebra.UnitLowerTriangular{Int64, S} where S<:AbstractMatrix{Int64}, α, β)/α = true, β = false/adjoint and transpose/fa = transpose, fb = transpose @test returned_mat === Ccopy