Get the top-level g node in an SVG document
在SVG文档中获取顶级G级节点
译者:生物统计家园网 机器人LoveR
描述----------Description----------
This function is a marginally convenient way to fetch the top-most g node in the SVG document that contains all the rendered components. This is the element with an id attribute whose value is 'surface0' and whose sub-nodes are typically of interest. The other part of the document is the defs which contain definitions that are used by sub-nodes of this g node.
这个函数是一个轻微便捷的方式获取最上面的g节点在SVG文件,其中包含所有的渲染组件。这是一个id属性的元素,其值是'surface0'和其子节点是典型的利益。该文件的另一部分是defs包含这个g节点的子节点的定义。