function SortByClockId (a, b, resolveConflict) {
  // Sort by ID if clocks are concurrent,
  // take the entry with a "greater" clock id
  return a.clock.id === b.clock.id
    ? resolveConflict(a, b)
    : a.clock.id < b.clock.id ? -1 : 1
}
Sort two entries by their clock id.
@param {Entry} a First entry to compare
@param {Entry} b Second entry to compare
@param {function(a, b)} resolveConflict A function to call if the clocks ids
are the same. The function should take in two entries and return 1 if the
first entry should be chosen and -1 if the second entry should be chosen.
@return {number} 1 if a is greater, -1 if b is greater
@private