Note: information on this page refers to Ceylon 1.1, not to the current release.
optional annotation
          
          The optional annotation is applied to module imports which are
          not strictly required by the module.
Usage
module com.example.foo "1.0" {
    optional import org.example.bar "4.5.1";
}
Description
An optional dependency will be loaded by the module runtime if it
          is available, but no error will occur if it is not available.
See also
- API documentation for optional
- Reference for annotations in general