function normalizeEcmaVersion(ecmaVersion,isModule){// Need at least ES6 for modules
if(isModule&&(!ecmaVersion||ecmaVersion<6)){ecmaVersion=6;}// Calculate ECMAScript edition number from official year version starting with
// ES2015, which corresponds with ES6 (or a difference of 2009).
if(ecmaVersion>=2015){ecmaVersion-=2009;}return ecmaVersion;}
Normalize ECMAScript version from the initial config
@param  {number} ecmaVersion ECMAScript version from the initial config
@param  {boolean} isModule Whether the source type is module or not
@returns {number} normalized ECMAScript version