docs: function getSetterFunctionHasOne(association, privateAssociationName, privateImplicitAssociationName) {
    this[privateAssociationName] = null;
  
    return (newModel) => {
      if (newModel && this[privateAssociationName] !== newModel) {
        if(!(newModel instanceof Model)) {
          throw new Error("Cannot set a non model entity onto this property. It should inherit from Model");
        }
  
        this[privateAssociationName] = newModel;
        this[privateImplicitAssociationName] = newModel.id;
  
        newModel[association.foreignName] = this;
      }
    };
  }