How to make a Swift framework submodule really private?

Question

I've found another question which brings more details regarding the problem and possible solutions. It seems like there is a known bug which is a subject for future improvements.

Objective C classes within an iOS Swift-based dynamic framework

I'm developing a framework in Swift and I'm using some Objective-C code inside the framework. So far my module map looks like this:

framework module MyModule {
    umbrella header "MyModule-umbrella.h"

    export *

    explicit module Private {
        header "MyTools.h"
    }
}

My concern is that all the APIs from MyTools.h are visible from outside the framework: for example, if you install the framework using Cocoapods, then you import MyModule into your application (not MyModule.Private), you are able to access MyTools.h which is not desirable and redundant. Is there any way to make MyTools invisible from outside the framework?

PS. I use Cocoapods to distribute the framework, here is my podspec (the most significant part):

s.module_map    = 'Pod/MyModule.modulemap'
s.frameworks    = 'CoreData', 'CoreTelephony', 'SystemConfiguration'
s.resources     = 'Pod/Classes/MessageStorage/*.xcdatamodeld'
s.public_header_files = 'Pod/Classes/**/*.h'
s.private_header_files = 'Pod/Classes/MyTools/**/*.h'
s.source_files  = 'Pod/Classes/**/*.{h,m,swift}'

PSS. My umbrella header does not import MyTools.h

PSSS. Just tried to exclude the header from the main module:

framework module MyModule {
    umbrella header "MyModule-umbrella.h"

    export *
    exclude header "MyTools.h"

    explicit module Private {
        header "MyTools.h"
    }
}

No luck.

Answer 1

I found another question which brings more details regarding the problem and possible solutions (which don't work though). It seems like there is a known bug which is a subject for future improvements.

Objective C classes within an iOS Swift-based dynamic framework