Create a new font scale attribute.
The effect of this attribute is to change the font size of a run, relative to the size of preceding run.
a pango.types.FontScale value, which indicates font size change relative to the size of the previous run.
the newly allocated pango.attribute.Attribute, which should be freed with pango.attribute.Attribute.destroy
Create a new font scale attribute.
The effect of this attribute is to change the font size of a run, relative to the size of preceding run.