func Reshuffle(s beam.Scope, col beam.PCollection) beam.PCollection {
	s = s.Scope("Reshuffle")
	col = beam.ParDo(s, func(x beam.X) (int, beam.X) {
		return rand.Int(), x
	}, col)
	col = beam.GroupByKey(s, col)
	return beam.ParDo(s, func(key int, values func(*beam.X) bool, emit func(beam.X)) {
		var x beam.X
		for values(&x) {
			emit(x)
		}
	}, col)
}
Reshuffle takes a PCollection<A> and shuffles the data to help increase parallelism.
package morebeam
import (
	"math/rand"
	"github.com/apache/beam/sdks/go/pkg/beam"
)