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: custom_http.go
    path of file: ./repos/casdoor/email
    
    the code of the file until where you have to start completion: // Copyright 2023 The Casdoor Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package email

import (
	"fmt"
	"net/http"
	"net/url"
	"strings"

	"github.com/casdoor/casdoor/proxy"
)

type HttpEmailProvider struct {
	endpoint string
	method   string
}

func NewHttpEmailProvider(endpoint string, method string) *HttpEmailProvider {
	client := &HttpEmailProvider{
		endpoint: endpoint,
		method:   method,
	}
	return client
}

fu
    
func (c *HttpEmailProvider) Send(fromAddress string, fromName string, toAddress string, subject string, content string) error {
	var req *http.Request
	var err error
	if c.method == "POST" {
		formValues := url.Values{}
		formValues.Set("fromName", fromName)
		formValues.Set("toAddress", toAddress)
		formValues.Set("subject", subject)
		formValues.Set("content", content)
		req, err = http.NewRequest(c.method, c.endpoint, strings.NewReader(formValues.Encode()))
		if err != nil {
			return err
		}

		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	} else if c.method == "GET" {
		req, err = http.NewRequest(c.method, c.endpoint, nil)
		if err != nil {
			return err
		}

		q := req.URL.Query()
		q.Add("fromName", fromName)
		q.Add("toAddress", toAddress)
		q.Add("subject", subject)
		q.Add("content", content)
		req.URL.RawQuery = q.Encode()
	} else {
		return fmt.Errorf("HttpEmailProvider's Send() error, unsupported method: %s", c.method)
	}

	httpClient := proxy.DefaultHttpClient
	resp, err := httpClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("HttpEmailProvider's Send() error, custom HTTP Email request failed with status: %s", resp.Status)
	}

	return err
}