packages/pcb-stackup/index.js
function renderStackup(stackupLayers, next) {
        var stackup = createStackup(stackupLayers, options)
        stackup.layers = stackupLayers
        next(null, stackup)
      }
function renderStackup(stackupLayers, next) {
        var stackup = createStackup(stackupLayers, options)
        stackup.layers = stackupLayers
        next(null, stackup)
      }
function renderStackup ( stackupLayers , next ) { var stackup = createStackup ( stackupLayers , options ) stackup . layers = stackupLayers next ( null , stackup ) }
using the result of renderAllLayers, build the stackup
using the result of renderAllLayers build the stackup