copyFromURL(copySource, options) {
        return this.client.sendOperationRequest({ copySource, options }, copyFromURLOperationSpec);
    }
The Copy From URL operation copies a blob or an internet resource to a new blob. It will not return
a response until the copy is complete.
@param copySource Specifies the name of the source page blob snapshot. This value is a URL of up to
                  2 KB in length that specifies a page blob snapshot. The value should be URL-encoded as it would
                  appear in a request URI. The source blob must either be public or must be authenticated via a shared
                  access signature.
@param options The options parameters.