set_duplex
Description:
Sets the value of gtk_print_settings_duplex.
Parameters:
| this |
a `GtkPrintSettings` |
| duplex |
a `GtkPrintDuplex` value |
Sets the value of gtk_print_settings_duplex.
| this |
a `GtkPrintSettings` |
| duplex |
a `GtkPrintDuplex` value |