         continue unless symbol?
         levels[symbol.zIndex] ?= []
         levels[symbol.zIndex].push use = doc.createElementNS SVGNS, 'use'
-        use.setAttribute Drawing.hrefAttr(), '#' + symbol.id
+        use.setAttribute @hrefAttr(), '#' + symbol.id
         use.setAttribute 'x', x
         use.setAttribute 'y', y
         scaleX = scaleY = 1

      ## it to make multiple versions, but keep track of which are the same.
      value = @function key
      if value?
        @map[key] = Symbol.parse key, value, dirname
      else
        value
    else

        node.setAttribute 'height', height or use.getAttribute 'height'
        symbol.setAttribute 'viewBox', "0 0 #{width} #{height}"
        symbol.appendChild node
      use.setAttribute @hrefAttr(), '#' + inlineImages[attributes]
      false
    ## Lay out the symbols in the drawing via SVG <use>.
    viewBox = [0, 0, 0, 0]  ## initially x-min, y-min, x-max, y-max
