@Returns: @closure: @notify_data: @notify_func: @closure: @notify_data: @notify_func: @closure: @notify_data: @notify_func: @closure: @notify_data: @notify_func: @name: @nick: @blurb: @default_value: @flags: @Returns: @signal_id: @closure: @Returns: @Returns: @signal_name: @itype: @signal_flags: @class_offset: @accumulator: @accu_data: @c_marshaller: @return_type: @n_params: @Varargs: Determines if @value is a #GValue whose type conforms to @type. @value: A valid #GValue structure. @type: A #GType value. @Returns: #TRUE if @value is a #GValue of @type or #FALSE if not. @src_value: @dest_value: @Returns: @value_type1: @value_type2: @func: @value_type1: @value_type2: @Returns: @value1: @value2: @Returns: