Angular testing issues

[Romko775]

After using library as service the components are failing with

NullInjectorError: R3InjectorError(DynamicTestModule)[Gallery -> Gallery]: 
          NullInjectorError: No provider for Gallery!
        error properties: Object({ ngTempTokenPath: null, ngTokenPath: [ 'Gallery', 'Gallery' ] })
        NullInjectorError: R3InjectorError(DynamicTestModule)[Gallery -> Gallery]: 
          NullInjectorError: No provider for Gallery!

&

NullInjectorError: R3InjectorError(DynamicTestModule)[Gallery -> Overlay -> Overlay]: 
          NullInjectorError: No provider for Overlay!
        error properties: Object({ ngTempTokenPath: null, ngTokenPath: [ 'Gallery', 'Overlay', 'Overlay' ] })
        NullInjectorError: R3InjectorError(DynamicTestModule)[Gallery -> Overlay -> Overlay]: 
          NullInjectorError: No provider for Overlay!