```json
{
    "no": ["no"],
    "yes": ["yes"]
}
```
In this case, the relationship between the feature (endocr_01) and the task (presence of chronic heart failure) is directly specified in the feature description. If the patient has diabetes mellitus in the anamnesis (endocr_01 = "yes"), it indicates the presence of chronic heart failure. Conversely, if the patient does not have diabetes mellitus in the anamnesis (endocr_01 = "no"), it suggests the absence of chronic heart failure. Therefore, the possible values of endocr_01 for the target class "no" are ["no"], and the possible values of endocr_01 for the target class "yes" are ["yes"].