Modules are often about a single function. But the function has helper functions that are not part of the API. Then maybe some functions that are part of the API which help use that function. Sometimes functions beget families.
If a function is built on several helper functions, it may be that those same helper functions can also be used to make other, related things which round out the functionality area. Perhaps they provide an API that's easier to use for different scenarios or whatever.
If a function is built on several helper functions, it may be that those same helper functions can also be used to make other, related things which round out the functionality area. Perhaps they provide an API that's easier to use for different scenarios or whatever.