I would like to draw an integration contour which is pretty easy I think, but I am a newbie at the Tikz package. The integration contour goes from
-iinfinity to +iinfinity
parallel to the Imaginary axis but not exactly on it, rather slightly to the left (or right) of it. The integration contour also has a semicircle on it somewhere near the origin but not exactly on the origin.
I guess I'm looking for an indented contour but not the usual ones where one go from -infinity to + infinity with a jump over a pole as in the following picture but like I said I would like it to go vertically.
I also found this picture, I want something very close to this. If I get some help getting what is in the picture in the link I think I can manage doing the rest myself.
Please, any help would be appreciated, thanks.