code: def _load_dependency(cls, tile, dep, family):
          
  
          depname = dep['unique_id']
          depdir = os.path.join(tile.folder, 'build', 'deps', depname)
          deppath = os.path.join(depdir, 'module_settings.json')
  
          if not os.path.exists(deppath):
              raise BuildError("Could not find dependency", dependency=dep)
  
          try:
              deptile = IOTile(depdir)
          except DataError as exc:
              raise BuildError("Could not find dependency", dependency=dep, error=exc)
  
          merge_dicts(family['architectures'], deptile.architectures.copy())
docs: Load a dependency from build/deps/<unique_id>.