Check the coverage of JSON data objects deleivered by the calls

[langeipk]

This could provide a quantification about the number of attributes that are filled. Because, we observed, although a call is implemented the seleivered result is sparse. So this could used as hint about information capacity of information system used in Agronomy community and helps to consolidate BrAPI data types. For example tag attributes, that are very rarely filled as obsolete candidate.