public GSettings(string schema)
        {
            var gss = new GSettingsSchemaSource();

            _gSettingsSchema = gss.Lookup(schema, true);
            if (_gSettingsSchema == null)
            {
                throw new GSettingsSchemaException($"Settings Schema not found or not installed: {schema}");
            }

            GSettingsPtr = PInvokes.GSettings.New(schema);
        }
        internal GSettings(IntPtr rawGSettings, string schema)
        {
            if (rawGSettings == IntPtr.Zero)
            {
                throw new GSettingsSchemaException($"Settings Schema not found or not installed: {schema}");
            }

            var gss = new GSettingsSchemaSource();

            _gSettingsSchema = gss.Lookup(schema, true);

            GSettingsPtr = rawGSettings;
        }