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: retrystrategy.go
    path of file: ./repos/juju/api/agent/retrystrategy
    
    the code of the file until where you have to start completion: // Copyright 2016 Canonical Ltd.
// Copyright 2016 Cloudbase Solutions
// Licensed under the AGPLv3, see LICENCE file for details.

package retrystrategy

import (
	"fmt"

	"github.com/juju/errors"
	"github.com/juju/names/v5"

	"github.com/juju/juju/api/base"
	apiwatcher "github.com/ju
    
func (c *Client) RetryStrategy(agentTag names.Tag) (params.RetryStrategy, error) {
	var results params.RetryStrategyResults
	args := params.Entities{
		Entities: []params.Entity{{Tag: agentTag.String()}},
	}
	err := c.facade.FacadeCall("RetryStrategy", args, &results)
	if err != nil {
		return params.RetryStrategy{}, errors.Trace(err)
	}
	if len(results.Results) != 1 {
		return params.RetryStrategy{}, fmt.Errorf("expected 1 result, got %d", len(results.Results))
	}
	result := results.Results[0]
	if result.Error != nil {
		return params.RetryStrategy{}, errors.Trace(result.Error)
	}
	return *result.Result, nil
}