export var Evented = Class.extend(this);定义了基于事件的类，如Map、Marker等。Generally, events allow you to execute some function when something happens with an object，例如 leaflet通过引用处理事件监听，例如 删除之前添加的监听,若未指定函数，会删除对象某个事件的所有监听函数 ...
Company was established in Germany. One of the leading makers of colored pencils.Either the Derwent Pencil Company was the first company to design and manufacture the watercolour pencil, or Lyra invented the watersoluble colored pencil in 1930. I am not sure which company evented it ...
