'Checks if the currently set koji command is valid
:return: True or False'

def is_command_valid(self):

    koji_command_ok = True
    if (not os.path.isfile(self.command)):
        logging.error('Koji    command    "%s"    is    not    a    regular    file', self.command)
        koji_command_ok = False
    if (not os.access(self.command, os.X_OK)):
        logging.warn('Koji    command    "%s"    is    not    executable:    this    is    not    fatal    but    indicates    an    unexpected    situation', self.command)
    if (self.command not in self.CONFIG_MAP.keys()):
        logging.error('Koji    command    "%s"    does    not    have    a    configuration    file    associated    to    it', self.command)
        koji_command_ok = False
    return koji_command_ok
