def eager_load(assoc)
      relation = assoc.prepare(self)

      if assoc.override?
        relation.(assoc)
      else
        relation.preload_assoc(assoc)
      end
    end
def eager_load(assoc)
      relation = assoc.prepare(self)

      if assoc.override?
        relation.(assoc)
      else
        relation.preload_assoc(assoc)
      end
    end
Return a graph node prepared by the given association

 @param [Association] assoc An association object

 @return [Relation]

 @api public