has_key

Looks whether the key file has the key key in the group group_name.

Note that this function does not follow the rules for [struct@GLib.Error] strictly; the return value both carries meaning and signals an error. To use this function, you must pass a [struct@GLib.Error] pointer in throws, and check whether it is not `NULL` to see if an error occurred.

Language bindings should use [method@GLib.KeyFile.get_value] to test whether a key exists.

Parameters:

this	a key file
group_name	a group name
key	a key name

Returns:

true if key is a part of group_name, false otherwise