function _cmdWriteFilteredResponse(root, path, resData) {
    var pathKey  = getPathKey(root),
        callback = _requests[pathKey][resData.id];

    if (callback) {
        callback(resData);
    } else {
        console.warn("writeFilteredResponse: Missing callback for %s. This command must only be called after a requestFilter event has fired for a path.", pathJoin(root, path));
    }
}
@private
Overrides the server response from static middleware with the provided
response data. This should be called only in response to a filtered request.

@param {string} path The absolute path of the server
@param {string} root The relative path of the file beginning with a forward slash "/"
@param {!Object} resData Response data to use