$response = Requests::get('https://github.com/timeline.json');

第2个参数：$headers = array() 为附加的头部请求

array('Accept' => 'application/json')

第3个参数：$options = array() 为配置参数

`timeout`: 设置响应超时时间
(integer, seconds, default: 10)
`useragent`: 设置发送到服务器的用户代理
(string, default: php-requests/$version)
`follow_redirects`: 是否允许3XX重定向
(boolean, default: true)
`redirects`: How many times should we redirect before erroring?
(integer, default: 10)
`blocking`: Should we block processing on this request?
(boolean, default: true)
`filename`: File to stream the body to instead.
(string|boolean, default: false)
`auth`: Authentication handler or array of user/password details to use for Basic authentication
(Requests_Auth|array|boolean, default: false)
`proxy`: Proxy details to use for proxy by-passing and authentication
(Requests_Proxy|array|boolean, default: false)
`idn`: Enable IDN parsing
(boolean, default: true)
`transport`: Custom transport. Either a class name, or a transport object. Defaults to the first working transport from
{@see getTransport()}
(string|Requests_Transport, default: {@see getTransport()})
`hooks`: Hooks handler.
(Requests_Hooker, default: new Requests_Hooks())
`verify`: Should we verify SSL certificates? Allows passing in a custom
certificate file as a string. (Using true uses the system-wide root
certificate store instead, but this may have different behaviour
across transports.)
(string|boolean, default: library/Requests/Transport/cacert.pem)
`verifyname`: Should we verify the common name in the SSL certificate?
(boolean: default, true)

2、使用POST发送请求获取远程数据 Requests::post($url, $headers = array(), $data = array(), $options = array());