code: function onSameRow(a, b, minimumStartDifference) {
    return (
      // Occupies the same start slot.
      Math.abs(b.start - a.start) < minimumStartDifference ||
      // A's start slot overlaps with b's end slot.
      (b.start > a.start && b.start < a.end)
    )
  }
docs: Return true if event a and b is considered to be on the same row.