所有加载器的基类
当创建一个新的 [name], 将调用此基类。
跨域字符串,用于实现跨域,以便从允许CORS从其他域加载url。默认为"anonymous"。
*[name].Handlers* is a special object normally used by other loaders like [page:GLTFLoader] or [page:MTLLoader]. It provides an
API that allows the definition of special mappings: What loaders should be used in order to load specific files. A typical use case
is to overwrite the default loader for textures.
Note: It's only possible to use *[name].Handlers* if the respective loader support the usage.
[page:Object regex] — A regular expression.
[page:Loader loader] — The loader.
Registers a loader with the given regular expression.
[page:String file] — The file path.
Can be used to retrieve the registered loader for the given file path.