in lib/generator.js [1794:1803]
visitBuiltinStaticCall(ast, level) {
const moduleName = _name(ast.left.id);
const builtiner = this.builtin[moduleName];
if (!builtiner) {
throw new Error('un-implemented');
}
const func = _name(ast.left.propertyPath[0]);
builtiner[func](ast, level, ast.isAsync && this.isAsyncFunction);
}