If this is not of type g_dbus_message_type_error does nothing and returns false.
Otherwise this method encodes the error in this as a Error using set_dbus_error using the information in the g_dbus_message_header_field_error_name header field of this as well as the first string item in this's body.
| this |
A DBusMessage. |
|
true if throws was set, false otherwise. |