docs: def _unpack_aar(self, aar, arch):
          '''Unpack content of .aar bundle and copy to current dist dir.'''
          with temp_directory() as temp_dir:
              name = splitext(basename(aar))[0]
              jar_name = name + '.jar'
              info("unpack {} aar".format(name))
              debug("  from {}".format(aar))
              debug("  to {}".format(temp_dir))
              shprint(sh.unzip, '-o', aar, '-d', temp_dir)
  
              jar_src = join(temp_dir, 'classes.jar')
              jar_tgt = join('libs', jar_name)
              debug("copy {} jar".format(name))
              debug("  from {}".format(jar_src))
              debug("  to {}".format(jar_tgt))
              ensure_dir('libs')
              shprint(sh.cp, '-a', jar_src, jar_tgt)
  
              so_src_dir = join(temp_dir, 'jni', arch.arch)
              so_tgt_dir = join('libs', arch.arch)
              debug("copy {} .so".format(name))
              debug("  from {}".format(so_src_dir))
              debug("  to {}".format(so_tgt_dir))
              ensure_dir(so_tgt_dir)
              so_files = glob.glob(join(so_src_dir, '*.so'))
              for f in so_files:
                  shprint(sh.cp, '-a', f, so_tgt_dir)