anchor.diff:  |ntile(_expression_)
   |java.lang.Long
   |java.lang.Long
  -|bucket index ranging from `0` to _expression - 1_, dividing the partition as equally as possible
  +|bucket index ranging from `0` to `expression - 1`, dividing the partition as equally as possible
   
   |lead(_expression_ [, _offset_ [, _default_]])
   |any [, java.lang.Long [, same as _expression_ type]]
  
positive.code: |rowNumber()
  |
  |java.lang.Long
  |number of the current row within its partition, counting from 0
  
  |rank()
  |
  
negative.code: |count()
  |
  |java.lang.Long
  |number of rows, similar to `count(*)` in SQL
  
  |count(_expression_)
  |any
  