If I understand your question correctly, you can use Module#include?:
Man.include?(Features)
For example:
module M
end
class C
include M
end
C.include?(M) # => true
Other ways
Checking Module#included_modules
This works, but it’s a bit more indirect, since it generates intermediate included_modules array.
C.included_modules.include?(M) # => true
since C.included_modules has a value of [M, Kernel]
Checking Module#ancestors
C.ancestors.include?(M) #=> true
since C.ancestors has a value of [C, M, Object, Kernel, BasicObject]
Using operators like <
The Module class also declares several comparison operators:
Module#<Module#<=Module#==Module#>=Module#>
Example:
C < M # => true