code: def mark_targets_as_explicit (self, target_names):
          
  
          # Record the name of the target, not instance, since this
          # rule is called before main target instaces are created.
          assert is_iterable_typed(target_names, basestring)
          self.explicit_targets_.update(target_names)
docs: Add 'target' to the list of targets in this project
          that should be build only by explicit request.