is_socket
Description:
test if socket
This returns true if and only if there is a Unix domain socket with the given path name.
If the optional flag followsymlinks is true, then a symlink (or chain of symlinks) that ends with a socket also causes the 
      function to return true.
See also stat.
Parameters:
| this | 
           A GuestfsSession object  | 
      
| optargs | 
           a GuestfsIsSocket containing optional arguments  | 
      
Returns:
| 
           the returned value, or -1 on error  |