code: function escapeSolrChars(str) {
      let solrChars = /(\+|\-|\!|\(|\)|\{|\}|\[|\]|\^|\"|\~|\*|\?|\:|\/|\&{2}|\|{2}|\s)/gm;
      return str.replace(solrChars, (match) => match.replace(/(.)/gm, '\\$1') );
  }
docs: Simple solr special char escaper. Based on
  https://cwiki.apache.org/confluence/display/solr/The+Standard+Query+Parser
  @param  {String} str - The string to escape
  @return {String} - The same string with all special solr chars escaped with '\'