function applyStyle(style, target, contextNode) {
  target = target || document.head;
  let after = (contextNode && contextNode.nextSibling) ||
    target.firstChild;
  target.insertBefore(style, after);
  if (!lastHeadApplyNode) {
    lastHeadApplyNode = style;
  } else {
    // only update lastHeadApplyNode if the new style is inserted after the old lastHeadApplyNode
    let position = style.compareDocumentPosition(lastHeadApplyNode);
    if (position === Node.DOCUMENT_POSITION_PRECEDING) {
      lastHeadApplyNode = style;
    }
  }
}
@param {HTMLStyleElement} style
@param {?Node} target
@param {?Node} contextNode