Unable to create multi-values prop from derived data functions

Using a derived data to set some props of documents, it's not possible set multi-valued property when the property is not present before the derived function runs.

Doing:
parameters.put(ATTR_KEYS, returnedValues);
where “ATTR_KEYS” is the name of the prop and “returnedValues” is an array of Value objects, if the prop is already present, it’s work, but when not present, the derived function try to create it but with single-valued, and store only the first element of the array.

Docs about derived data: https://documentation.bloomreach.com/library/concepts/content-repository/derived-data.html