Imports all features and extensions and all their dependencies.

    :param Registry dest: Destination API
    :param Registry src: Source Registry
    :param str api: Only import Features with API name `api`, or None
                    to import all features.
    :param str profile: Only import Features with profile name `profile`,
                        or None to import all features.
    :param str support: Only import Extensions with this extension support
                        string, or None to import all extensions.
    :param filter_symbol: Optional symbol filter callable
    :type filter_symbol: Callable with signature
                         ``(symbol_type:str, symbol_name:str) -> bool``

def import_registry(dest, src, api=None, profile=None, support=None,
                    filter_symbol=None):
    """Imports all features and extensions and all their dependencies.

    :param Registry dest: Destination API
    :param Registry src: Source Registry
    :param str api: Only import Features with API name `api`, or None
                    to import all features.
    :param str profile: Only import Features with profile name `profile`,
                        or None to import all features.
    :param str support: Only import Extensions with this extension support
                        string, or None to import all extensions.
    :param filter_symbol: Optional symbol filter callable
    :type filter_symbol: Callable with signature
                         ``(symbol_type:str, symbol_name:str) -> bool``
    """
    if filter_symbol is None:
        filter_symbol = _default_filter_symbol
    for x in src.get_features(api):
        import_feature(dest, src, x.name, api, profile, filter_symbol)
    for x in src.get_extensions(support):
        import_extension(dest, src, x.name, api, profile, filter_symbol)