code: function copy(el, text) {
      var result, lastText;
  
      if (text) {
          lastText = el.value;
          el.value = text;
      } else {
          text = el.value;
      }
  
      el.value = multiLineTrim(text);
  
      try {
          el.select();
          result = document.execCommand('copy');
      } catch (err) {
          result = false;
      } finally {
          if (lastText !== undefined) {
              el.value = lastText;
          }
          el.blur();
      }
      return result;
  }
docs: 1. Trim the text in the given input element
  2. select it
  3. copy it to the clipboard
  4. deselect it
  5. return it
  @param {HTMLElement|HTMLTextAreaElement} el
  @param {string} [text=el.value] - Text to copy.
  @returns {undefined|string} Trimmed text in element or undefined if unable to copy.