Converts the @provider into a string representation in CSS
format.
Using gtk_css_provider_load_from_data() with the return value
from this function on a new provider created with
gtk_css_provider_new() will basically create a duplicate of
this @provider.
Converts the @provider into a string representation in CSS format.
Using gtk_css_provider_load_from_data() with the return value from this function on a new provider created with gtk_css_provider_new() will basically create a duplicate of this @provider.
Return: a new string representing the @provider.