moveNode (attr, newValue) {
      const selPts = path.selected_pts
      if (!selPts.length) { return }

      path.storeD()

      // Get first selected point
      const seg = path.segs[selPts[0]]
      const diff = { x: 0, y: 0 }
      diff[attr] = newValue - seg.item[attr]

      seg.move(diff.x, diff.y)
      path.endChanges('Move path point')
    }
@param {string} attr
@param {Float} newValue
@returns {void}