<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def consolidate_metadata(store, metadata_key='.zmetadata'):
 """ Consolidate all metadata for groups and arrays within the given store into a single resource and put it under the given key. This produces a single object in the backend store, containing all the metadata read from all the zarr-related keys that can be found. After metadata have been consolidated, use :func:`open_consolidated` to open the root group in optimised, read-only mode, using the consolidated metadata to reduce the number of read operations on the backend store. Note, that if the metadata in the store is changed after this consolidation, then the metadata read by :func:`open_consolidated` would be incorrect unless this function is called again. .. note:: This is an experimental feature. Parameters store : MutableMapping or string Store or path to directory in file system or name of zip file. metadata_key : str Key to put the consolidated metadata under. Returns ------- g : :class:`zarr.hierarchy.Group` Group instance, opened with the new consolidated metadata. See Also -------- open_consolidated """

    store = normalize_store_arg(store)

    def is_zarr_key(key):
        return (key.endswith('.zarray') or key.endswith('.zgroup') or
                key.endswith('.zattrs'))

    out = {
        'zarr_consolidated_format': 1,
        'metadata': {
            key: json_loads(store[key])
            for key in store if is_zarr_key(key)
        }
    }
    store[metadata_key] = json_dumps(out)
    return open_consolidated(store, metadata_key=metadata_key)