We can use some rspec methods: 
```ruby  
  before(:each) do
    @tmp = Astute::MClient
  end
  
  after(:each) do
    Astute::MClient = @tmp
  end
  
  let(:ctx) do
    mock_ctx()
  end
```
and remove from every tests this lines:
```ruby
ctx = mock_ctx()
```
```ruby
tmp = Astute::MClient
Astute::MClient = tmp
```