public function validate(string $attribute, mixed $value, Closure $fail): void 	{ 		$validatedModel = $this->request->id;  		// relationModel exists in db 		if ($this->relationModel::find($value)) { 			return; 		}  		$detailsFieldName = $this->relationModel->detailsFieldName();  		// relationModel does not exists in db, but exists in hardcoded data of validatedModel 		if (isset($validatedModel->{$detailsFieldName}['id']) && ($value == $validatedModel->{$detailsFieldName}['id'])) { 			$this->request->merge([$attribute => null]);  			return; 		}  		// relationModel does not exist in db nor in hardcoded data of validatedModel 		$fail('validation.custom.' . $this->relationModel->validationErrorMessageKey())->translate([ 			'model' => $this->relationModel->getShortClassName(), 		]); 	}