code: function getPropertyForAssociation(forEntity, entity) {
    let associations = forEntity.getMeta().fetch('associations');
  
    return Object.keys(associations).filter(key => {
      return associations[key].entity === entity.getResource();
    })[0];
  }
docs: Get the property of the association on this entity.
  
  @param {Entity} forEntity
  @param {Entity} entity
  
  @return {string}