code: def migrate_1to2(store):
      
  
      # migrate metadata
      from zarr import meta_v1
      meta = meta_v1.decode_metadata(store['meta'])
      del store['meta']
  
      # add empty filters
      meta['filters'] = None
  
      # migration compression metadata
      compression = meta['compression']
      if compression is None or compression == 'none':
          compressor_config = None
      else:
          compression_opts = meta['compression_opts']
          codec_cls = codec_registry[compression]
          if isinstance(compression_opts, dict):
              compressor = codec_cls(**compression_opts)
          else:
              compressor = codec_cls(compression_opts)
          compressor_config = compressor.get_config()
      meta['compressor'] = compressor_config
      del meta['compression']
      del meta['compression_opts']
  
      # store migrated metadata
      store[array_meta_key] = encode_array_metadata(meta)
  
      # migrate user attributes
      store[attrs_key] = store['attrs']
      del store['attrs']
docs: Migrate array metadata in `store` from Zarr format version 1 to
      version 2.
  
      Parameters
      ----------
      store : MutableMapping
          Store to be migrated.
  
      Notes
      -----
      Version 1 did not support hierarchies, so this migration function will
      look for a single array in `store` and migrate the array metadata to
      version 2.