code: func (t *Pot) EachBin(val Val, pof Pof, po int, f func(int, int, func(func(val Val) bool) bool) bool) {
  	t.eachBin(val, pof, po, f)
  }
docs: // EachBin iterates over bins of the pivot node and offers iterators to the caller on each
  // subtree passing the proximity order and the size
  // the iteration continues until the function's return value is false
  // or there are no more subtries