code: function precompile(tmpl, outputH, tmplRule) {
    var root = _createAstRoot();
  
    if (tmpl.quasis) {
      var _tmpl = tmpl,
          quasis = _tmpl.quasis,
          isExpression = _tmpl.isExpression,
          isCss = _tmpl.isCss;
      tmpl = compileStringTmpl.call({
        tmplRule: tmplRule,
        outputH: outputH,
        onlyParse: true,
        isExpression: isExpression,
        isCss: isCss
      }, quasis);
    } else if (isString(tmpl)) {
      tmpl = compileStringTmpl.call({
        tmplRule: tmplRule,
        outputH: outputH,
        onlyParse: true
      }, tmpl);
    }
  
    checkElem(tmpl._njTmpl, root, tmplRule);
    return buildRuntime(root.content, root, !outputH);
  }
docs: Precompile template