This operator calculated a list of top elements regarding a scoring function. Only if the top elements change, an output will be produced. Additionally, the object that triggered the new calculation is send to output
Outputschema is List<TUPLE>, TUPLE
Remark: Use  or elementAt to access elements in List and in TUPLE
- scoringFunction [Expression]: An expression that must return a numerical value
- k [Integer]: Number of elements that should be treated
- descending [Boolean]: The standardcase is that the higher the score, the higher the rank. Set to false if the higher the score, the lower the rank.