config/config.go
func (c *Config) Set(section string, key string, value string) {
	_, ok := c.config[section]
	if !ok {
		c.config[section] = make(map[string]string)
	}
	c.config[section][key] = value
}
func (c *Config) Set(section string, key string, value string) {
	_, ok := c.config[section]
	if !ok {
		c.config[section] = make(map[string]string)
	}
	c.config[section][key] = value
}
// Set function updates the value of a key in the configuration. Function
// Set() is exactly the same as function Add().