class CommandSink:
    '''An interface for processing commands originating from the user'''

    def process_command(self, command):
        '''Parses and executes a user command
        command: str, the command from the user
        '''
        raise NotImplementedError()

    def toplevel_commands(self):
        '''Returns a list of toplevel commands
        returns: list of str
        '''
        raise NotImplementedError()

5ed0ff170b5448f00a857058fde103cad238f5ee
<mask token>

class CommandSink:
    <mask token>
    <mask token>

    def toplevel_commands(self):
        """Returns a list of toplevel commands
        returns: list of str
        """
        raise NotImplementedError()

class CommandSink:
    <mask token>

    def process_command(self, command):
        """Parses and executes a user command
        command: str, the command from the user
        """
        raise NotImplementedError()

    def toplevel_commands(self):
        """Returns a list of toplevel commands
        returns: list of str
        """
        raise NotImplementedError()

class CommandSink:
    """An interface for processing commands originating from the user"""

    def process_command(self, command):
        """Parses and executes a user command
        command: str, the command from the user
        """
        raise NotImplementedError()

    def toplevel_commands(self):
        """Returns a list of toplevel commands
        returns: list of str
        """
        raise NotImplementedError()

class CommandSink:
    '''An interface for processing commands originating from the user'''

    def process_command(self, command):
        '''Parses and executes a user command
        command: str, the command from the user
        '''
        raise NotImplementedError()

    def toplevel_commands(self):
        '''Returns a list of toplevel commands
        returns: list of str
        '''
        raise NotImplementedError()
