setStrokeAttrMethod = (attr, val) => {
  const selectedElements = svgCanvas.getSelectedElements()
  svgCanvas.setCurShape(attr.replace('-', '_'), val)
  const elems = []

  let i = selectedElements.length
  while (i--) {
    const elem = selectedElements[i]
    if (elem) {
      if (elem.tagName === 'g') {
        walkTree(elem, (e) => { if (e.nodeName !== 'g') { elems.push(e) } })
      } else {
        elems.push(elem)
      }
    }
  }
  if (elems.length > 0) {
    svgCanvas.changeSelectedAttribute(attr, val, elems)
    svgCanvas.call('changed', selectedElements)
  }
}
Set the given stroke-related attribute the given value for selected elements.
@function module:elem-get-set.SvgCanvas#setStrokeAttr
@param {string} attr - String with the attribute name
@param {string|Float} val - String or number with the attribute value
@fires module:elem-get-set.SvgCanvas#event:changed
@returns {void}