Example> Then I looked more closely and by gum , found a rainbow lurking in the mist ahead.
Example> But what he was really good at was machines. By gum, he could make them go! He loved anything mechanical, did Walter.
Example> If he were elected , by gum , things would be different
B) in general
Example> When we produce reporters who purport to be devoted to balance and impartiality , by gum , they deliver just that.
"By love, by gum"
"Eat bone by gum"
by gum, you'd figure it out, by yourself