我有3个模型:classInterestincludeMongoid::Documenthas_many:user_hobbyendclassUserHobbyincludeMongoid::Documentfield:contacts,:type=>Arraybelongs_to:interest,:foreign_key=>"interest",inverse_of:nilbelongs_to:interest,:foreign_key=>"related_interests",inverse_of:nilembedded_in:userendclassUserincludeMon