svgPanZoom = function(elementOrSelector, options) {
  var svg = Utils.getSvg(elementOrSelector);

  if (svg === null) {
    return null;
  } else {
    // Look for existent instance
    for (var i = instancesStore.length - 1; i >= 0; i--) {
      if (instancesStore[i].svg === svg) {
        return instancesStore[i].instance.getPublicInstance();
      }
    }

    // If instance not found - create one
    instancesStore.push({
      svg: svg,
      instance: new SvgPanZoom(svg, options)
    });

    // Return just pushed instance
    return instancesStore[
      instancesStore.length - 1
    ].instance.getPublicInstance();
  }
}
Stores pairs of instances of SvgPanZoom and SVG
Each pair is represented by an object {svg: SVGSVGElement, instance: SvgPanZoom}

@type {Array}