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: rpc_client.go
    path of file: ./repos/go-micro/client
    
    the code of the file until where you have to start completion: package client

import (
	"context"
	"fmt"
	"sync"
	"sync/atomic"
	"time"

	"github.com/google/uuid"
	"github.com/pkg/errors"

	"go-micro.dev/v4/broker"
	"go-micro.dev/v4/codec"
	raw "go-micro.dev
    
func (r *rpcClient) Init(opts ...Option) error {
	r.mu.Lock()
	defer r.mu.Unlock()

	size := r.opts.PoolSize
	ttl := r.opts.PoolTTL
	tr := r.opts.Transport

	for _, o := range opts {
		o(&r.opts)
	}

	// update pool configuration if the options changed
	if size != r.opts.PoolSize || ttl != r.opts.PoolTTL || tr != r.opts.Transport {
		// close existing pool
		if err := r.pool.Close(); err != nil {
			return errors.Wrap(err, "failed to close pool")
		}

		// create new pool
		r.pool = pool.NewPool(
			pool.Size(r.opts.PoolSize),
			pool.TTL(r.opts.PoolTTL),
			pool.Transport(r.opts.Transport),
		)
	}

	return nil
}