How to use packages in class

Thanks Dave. In a somewhat related note: I have a .svh file with interfaces. I will

`include

this file in some other .sv file (since I cannot put interfaces in packages). If an interface itself references an enum from another package, do I import the package inside the interface or outside?

interface my_intf_i;
   import some_pkg::*; // is this allowed?
   some_enum_from_pkg_e my_enum;
   // other interface stuff
   // modport stuff
endinterface