module T::Helpers

def abstract! 

def abstract!
  Private::Abstract::Declare.declare_abstract(self, type: :abstract)
end

def final! 

def final!
  Private::Final.declare(self)
end

def interface! 

def interface!
  Private::Abstract::Declare.declare_abstract(self, type: :interface)
end

def mixes_in_class_methods(mod)

Except that it is statically analyzed by sorbet.

end
other.extend(mod)
def self.included(other)

Nearly equivalent to

Causes a mixin to also mix in class methods from the named module. 
def mixes_in_class_methods(mod)
  Private::Mixins.declare_mixes_in_class_methods(self, mod)
end

def sealed! 

def sealed!
  Private::Sealed.declare(self, Kernel.caller(1..1)&.first&.split(':')&.first)
end