code: func (c *Conn) Bind(upn, password string) (bool, error) {
  	if password == "" {
  		return false, nil
  	}
  
  	err := c.Conn.Bind(upn, password)
  	if err != nil {
  		if e, ok := err.(*ldap.Error); ok {
  			if e.ResultCode == ldap.LDAPResultInvalidCredentials {
  				return false, nil
  			}
  		}
  		return false, fmt.Errorf("Bind error (%s): %v", upn, err)
  	}
  
  	return true, nil
  }
docs: //Bind authenticates the connection with the given userPrincipalName and password
  //and returns the result or an error if one occurred.