code: function shimTrimLeft(string, chars) {
      string = string == null ? '' : String(string);
      if (!string) {
        return string;
      }
      if (chars == null) {
        return string.slice(trimmedLeftIndex(string))
      }
      chars = String(chars);
      return string.slice(charsLeftIndex(string, chars));
    }
docs: A fallback implementation of `trimLeft` to remove leading whitespace or
  specified characters from `string`.
  
  @private
  @param {string} string The string to trim.
  @param {string} [chars=whitespace] The characters to trim.
  @returns {string} Returns the trimmed string.