function GetAll(ancestor,classes)
    local allObjs = {}
    local function objPass(obj)
        for _,v in pairs(classes) do
            if (obj:IsA(v)) then
                return true
            end
        end
        return false
    end
    local function recurs(anc)
        for _,v in pairs(anc:GetChildren()) do
            if (objPass(v)) then
                table.insert(allObjs,v)
            end
            recurs(v)
        end
    end
    recurs(ancestor)
    return allObjs
end


-- Examples:
local parts = GetAll(game.Workspace.Model,{"BasePart"})
local all = GetAll(game.Workspace.Model,{"Instance"})
local foo = GetAll(game.Workspace.Model,{"SpawnLocation","Flag","ObjectValue"})