desc.to.merge into the fields in
desc. If replace.existing is FALSE, only fields in desc that
are not already set are affected. If TRUE, then fields that are
already set will be replaced as well.pangoFontDescriptionMerge(object, desc.to.merge, replace.existing)objectdesc.to.mergePangoFontDescription] the PangoFontDescription to merge from, or NULLreplace.existingTRUE, replace fields in desc with the
corresponding values from desc.to.merge, even if they
are already exist.desc.to.merge is NULL, this function performs nothing.