Means to sincerely emphasis your statement, without 2nd thought and a shadow of a doubt about what your saying.
"I swear, I'm gonna spark the next person who treads on my trainers, rags!"
"Your the only girl for me, don't pay any attention to your friends coz i love you, rags! (I love you is being emphasis, saying that his love is unquestionable no matter what anyone else says.)"