is there a way to make available a matlab package to all functions available in same .m file

I am working with matlab packages and I want to make a package available to all methods in same .m file. I am trying to import the package in main method of .m file and it seems to me that other functions in .m file are unable to access the package. I do not want to import package in all functions and want to avoid this situation. Is there a way to tackle this issue.