code: def generate_from_reference(target_reference, project, property_set_):
      
      assert isinstance(target_reference, basestring)
      assert isinstance(project, ProjectTarget)
      assert isinstance(property_set_, property_set.PropertySet)
      target, sproperties = resolve_reference(target_reference, project)
  
      # Take properties which should be propagated and refine them
      # with source-specific requirements.
      propagated = property_set_.propagated()
      rproperties = propagated.refine(sproperties)
  
      return target.generate(rproperties)
docs: Attempts to generate the target given by target reference, which
      can refer both to a main target or to a file.
      Returns a list consisting of
      - usage requirements
      - generated virtual targets, if any
      target_reference:  Target reference
      project:           Project where the reference is made
      property_set:      Properties of the main target that makes the reference