/**
 * As Recast is not preserving original quoting, we try to detect it.
 * See https://github.com/benjamn/recast/issues/171
 * and https://github.com/facebook/jscodeshift/issues/143
 * @return 'double', 'single' or null
 */
export default function detectQuoteStyle(j: any, ast: any): "double" | "single";