You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: conn_pool.go
    path of file: ./repos/faygo/vendor/github.com/couchbase/go-couchbase
    
    the code of the file until where you have to start completion: package couchbase

import (
	"crypto/tls"
	"errors"
	"sync/atomic"
	"time"

	"github.com/couchbase/gomemcached"
	"github.com/couchbase/gomemcached/client"
	"github.com/couchbase/goutils/logging"
)

// GenericMcdAuthHandler is a kind of AuthHandler that performs
// special auth exchange (like non-standard auth, possibly followed by
// select-bucket).
type GenericMcdAuthHandler interface {
	AuthHandler
	AuthenticateMemcachedConn(host string, conn *memcached.Client) error
}

// Error raised when a connecti
    
func newConnectionPool(host string, ah AuthHandler, closer bool, poolSize, poolOverflow int, tlsConfig *tls.Config, bucket string) *connectionPool {
	connSize := poolSize
	if closer {
		connSize += poolOverflow
	}
	rv := &connectionPool{
		host:        host,
		connections: make(chan *memcached.Client, connSize),
		createsem:   make(chan bool, poolSize+poolOverflow),
		mkConn:      defaultMkConn,
		auth:        ah,
		poolSize:    poolSize,
		tlsConfig:   tlsConfig,
		bucket:      bucket,
	}
	if closer {
		rv.bailOut = make(chan bool, 1)
		go rv.connCloser()
	}
	return rv
}