onst keyEls = div.querySelectorAll('svg > g[key]');
    for (let i = 0; i < keyEls.length; i++) {
      const keyEl = keyEls[i];
      const key = keyEl.getAttribute('key');
      const shapeEl = keyEl.children[0];
      const boundings = svgBoundings[shapeEl.tagName.toLowerCase()](shapeEl);
      const {
        left,
        right,
        top,
        bottom,
      } = boundings;
      const x1 = left * keyboardMatrix[0];
      const x2 = right * keyboardMatrix[0];
      const y1 = top * keyboardMatrix[1