func appendStaticKey(key string) keySetAddFunc {
	return func(m keySet, _ string) {
		m[key] = struct{}{}
	}
}
appendStaticKey adds the same transaction overlap key for every namespace
package crdb
import "strings"
type keySet map[string]struct{}
func newKeySet() keySet {
	return make(map[string]struct{})
}
type overlapKeyer interface {
	AddKey(keySet keySet, namespace string)
}
type keySetAddFunc func(keySet keySet, namespace string)
func (f keySetAddFunc) AddKey(keySet keySet, namespace string) {
	f(keySet, namespace)
}
var (
	noOverlapKeyer overlapKeyer = keySetAddFunc(noOverlap)
	prefixKeyer    overlapKeyer = keySetAddFunc(appendKeysFromNamespaceComponents)
	_              overlapKeyer = appendStaticKey("")
)
func noOverlap(_ keySet, _ string) {}