Takes a raw user input, initially from command line
        Later: 
            - check user credentials
            - rate bias
            - check for malicious commands

def get_command(self, mode, txt=''):
        """
        Takes a raw user input, initially from command line
        Later: 
            - check user credentials
            - rate bias
            - check for malicious commands
        """
        if mode == 'COMMAND':
            self.prompt = '> '
        elif mode == 'ADD':
            self.prompt = 'ADD > '
        elif mode == 'QUERY':
            self.prompt = '?? > '
        if txt == '':
            txt = input(self.prompt)
        return txt