chore: import upstream snapshot with attribution

internal/util/pool/pool.go

@@ -0,0 +1,38 @@
+// Package pool is a connection pool
+package pool
+
+import (
+	"time"
+
+	"go-micro.dev/v6/transport"
+)
+
+// Pool is an interface for connection pooling.
+type Pool interface {
+	// Close the pool
+	Close() error
+	// Get a connection
+	Get(addr string, opts ...transport.DialOption) (Conn, error)
+	// Release the connection
+	Release(c Conn, status error) error
+}
+
+// Conn interface represents a pool connection.
+type Conn interface {
+	// unique id of connection
+	Id() string
+	// time it was created
+	Created() time.Time
+	// embedded connection
+	transport.Client
+}
+
+// NewPool will return a new pool object.
+func NewPool(opts ...Option) Pool {
+	var options Options
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return newPool(options)
+}