scripts/build.js
function setValue (obj, prop, value) {
  if (value !== undefined && obj[prop] === undefined) {
    obj[prop] = value
  }
}
function setValue (obj, prop, value) {
  if (value !== undefined && obj[prop] === undefined) {
    obj[prop] = value
  }
}
function setValue ( obj , prop , value ) { if ( value !== undefined && obj [ prop ] === undefined ) { obj [ prop ] = value } }
Set a value on an object, if not already set.
Set a value on an object if not already set .