* Checks if a cached value for `key` exists. * @param key The key of the entry to check. * @return Returns `true` if an entry for `k

* The client invokes the SEARCH method to initiate a server-side search. The body * of the request defines the query. The server MUST emit an

* Check if the incoming request contains the "Content-Type" * header field, and it contains the give mime `type`. * * Examp

* Checks if value is undefined. * * @param value The value to check. * @return Returns true if value is undefined, else fal

* The DELETE method requests that the origin server remove the association * between the target resource and its current functionality. In e

* Initialize the server. * * - setup default configuration * - setup default middleware * - setup route refl

* The PUT method requests that the enclosed entity be stored under the supplied * Request-URI. If the Request-URI refers to an already existi

* 参数范围-180~180；一个参数时，Y轴坐标不变，X轴坐标延顺时针倾斜ax度；两个参数时，分别在X轴倾斜ax度，在Y轴倾斜ay度

* Reverses `array` so that the first element becomes the last, the second * element becomes the second to last, and so on. *

* The WebDAV COPY Method creates a duplicate of the source resource identified by * the Request-Uniform Resource Identifier (URI), in the des

* Executes the chained sequence to extract the unwrapped value. * * @alias _.toJSON, _.valueOf * * @return Returns

* Defers invoking the func until the current call stack has cleared. Any additional arguments are provided to * func when it’s invoked.

* Checks if value is empty. A value is considered empty unless it’s an arguments object, array, string, or * jQuery-like collection with a le

* 在X轴偏移tx，在Y轴偏移ty，在Z轴偏移tz，单位px

* @param {string} name Name of the index. * @return {(!Array.<number>|!Array.<Array.<number>>)} *

* 判断输入值是否为空

* Invokes the method at path of object. * @param object The object to query. * @param path The path of the method to invoke. *

* 透明度，参数范围 0~1

* 恢复之前保存过的坐标轴的缩放、旋转、平移信息

* Calculates n rounded up to precision. * * @param n The number to round up. * @param precision The precision to round up t

* Observes changes made to an object, which can then be retieved using generate

* 设置线条的结束端点样式。 * @param lineCap 线条的结束端点样式('butt'、'round'、'square')

* An alternative to _.reduce; this method transforms object to a new accumulator object which is the result of * running each of its own enum

* @param {number} n The numerator. * @param {number} d The denominator. * @return {number} The result of the integer division of n by d.

* Checks if value is a buffer. * * @param value The value to check. * @return Returns true if value is a buffer, else false

* 绘制图像，图像保持原始尺寸。 * @param imageResource 所要绘制的图片资源，通过 `chooseImage` 得到一个文件路径或者一个项目目录内的图片 * @param x 图像左上角的x坐标 * @param y 图像左上角的y坐标

* 获取数组中的内容（一般为第一个元素） * @param {array} arr 内容数组 * @return {string} 内容

* Issue a request: * * Examples: * * request('GET', '/users').end(callback) * request('/users').end(callback) * request('/users', callb