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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def open_group(store=None, mode='a', cache_attrs=True, synchronizer=None, path=None, chunk_store=None):
 """Open a group using file-mode-like semantics. Parameters store : MutableMapping or string, optional Store or path to directory in file system or name of zip file. mode : {'r', 'r+', 'a', 'w', 'w-'}, optional Persistence mode: 'r' means read only (must exist); 'r+' means read/write (must exist); 'a' means read/write (create if doesn't exist); 'w' means create (overwrite if exists); 'w-' means create (fail if exists). cache_attrs : bool, optional If True (default), user attributes will be cached for attribute read operations. If False, user attributes are reloaded from the store prior to all attribute read operations. synchronizer : object, optional Array synchronizer. path : string, optional Group path within store. chunk_store : MutableMapping or string, optional Store or path to directory in file system or name of zip file. Returns ------- g : zarr.hierarchy.Group Examples -------- <zarr.hierarchy.Group '/'> <zarr.hierarchy.Group '/'> True """


    # handle polymorphic store arg
    store = _normalize_store_arg(store)
    if chunk_store is not None:
        chunk_store = _normalize_store_arg(chunk_store)
    path = normalize_storage_path(path)

    # ensure store is initialized

    if mode in ['r', 'r+']:
        if contains_array(store, path=path):
            err_contains_array(path)
        elif not contains_group(store, path=path):
            err_group_not_found(path)

    elif mode == 'w':
        init_group(store, overwrite=True, path=path, chunk_store=chunk_store)

    elif mode == 'a':
        if contains_array(store, path=path):
            err_contains_array(path)
        if not contains_group(store, path=path):
            init_group(store, path=path, chunk_store=chunk_store)

    elif mode in ['w-', 'x']:
        if contains_array(store, path=path):
            err_contains_array(path)
        elif contains_group(store, path=path):
            err_contains_group(path)
        else:
            init_group(store, path=path, chunk_store=chunk_store)

    # determine read only status
    read_only = mode == 'r'

    return Group(store, read_only=read_only, cache_attrs=cache_attrs,
                 synchronizer=synchronizer, path=path, chunk_store=chunk_store)