docs: def merge(items, amap, load=False):
  
      """Merge list of tuples into dict amap, and optionally load source as value"""
  
      for target, source in items:
          if amap.get(target):
              logger.warn('overwriting {0}'.format(target))
          if load:
              amap[target] = open(source).read()
          else:
              amap[target] = source