def __init__(self, cmd, parameters, usage):
        """
        Stores command name and parameters.  Ensures that the ``dir_op`` flag
        is true if a certain command is being used.

        :param cmd: The name of the command, e.g. "rm".
        :param parameters: A dictionary of parameters.
        :param usage: A usage string

        """
        self.cmd = cmd
        self.parameters = parameters
        self.usage = usage
        if 'dir_op' not in parameters:
            self.parameters['dir_op'] = False
        if parameters not in 'follow_symlinks':
            self.parameters['follow_symlinks'] = True
        if 'source_region' not in parameters:
            self.parameters['source_region'] = None
        if self.cmd in ['sync', 'mb', 'rb']:
            self.parameters['dir_op'] = True
dataset/ETHPy150Open aws/aws-cli/awscli/customizations/s3/subcommands.py/CommandParameters.__init__/swapped operands of `not in`