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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 validate_schema_dict(schema):
 # type: (Dict[str, Any]) -> None """ Validate the schema. This raises iff either the schema or the master schema are invalid. If it's successful, it returns nothing. :param schema: The schema to validate, as parsed by `json`. :raises SchemaError: When the schema is invalid. :raises MasterSchemaError: When the master schema is invalid. """

    if not isinstance(schema, dict):
        msg = ('The top level of the schema file is a {}, whereas a dict is '
               'expected.'.format(type(schema).__name__))
        raise SchemaError(msg)

    if 'version' in schema:
        version = schema['version']
    else:
        raise SchemaError('A format version is expected in the schema.')

    master_schema_bytes = _get_master_schema(version)
    try:
        master_schema = json.loads(master_schema_bytes.decode('utf-8'))
    except ValueError as e:  # In Python 3 we can be more specific with
        # json.decoder.JSONDecodeError, but that
        # doesn't exist in Python 2.
        msg = ('The master schema is not a valid JSON file. The schema cannot '
               'be validated. Please file a bug report.')
        raise_from(MasterSchemaError(msg), e)

    try:
        jsonschema.validate(schema, master_schema)
    except jsonschema.exceptions.ValidationError as e:
        raise_from(SchemaError('The schema is not valid.'), e)
    except jsonschema.exceptions.SchemaError as e:
        msg = ('The master schema is not valid. The schema cannot be '
               'validated. Please file a bug report.')
        raise_from(MasterSchemaError(msg), e)