- Implement the Actor trait for any struct that will represent someone/something taking action in
your system. it could for example be an enum wrapping User/Organization/Service if those are
entities that can take action. 
- An entity is any object in your SpiceDB system
The Id type represents whatever rust type you’re using internally, since SpiceDB only uses
Strings to avoid having to convert and deal with errors everywhere we use trait bounds - FromStrand- Into<String>which a lot of common Id types like- Uuidor- u32already implement.
 
- Represents possible permissions on a - ResourceEasiest way to implement is implementing- Into<&'static str>for your enum, which can builder
achieved with- strum::IntoStaticStr
 
- Represents possible relations to an - EntityEasiest way to implement is implementing- Into<&'static str>for your enum, which can builder
achieved with- strum::IntoStaticStr
 
- A resource is any - Entitythat also has- Permissionsassociated