Today when you get into a taxi, you will find an umbrella left behind by a previous passenger. It will be yours for the taking.
"Take me to the railyard," tell the cabby.
"The rail-yard?" the cabby will say. "That's been abandoned for years. There's not a soul around."
Hold up the umbrella and say, "Exactly. I gotta test this thing out."
When you get to the rail-yard, pay the cabby to wait for you, but tell him to park his cab behind one of the old train-cars should he need the cover. Walk about 500 paces into the field of empty train tracks until you're as far away as you can be from any hobos who might be sleeping out of sight. Then you should raise the umbrella pointed out away from you towards the empty expanse and push the button.
If the umbrella opens out without any gunfire, that means the button alone is not a trigger for a hidden pistol. But it could still be armed by twisting the handle in its base. Or the handle could pull out of the umbrella to reveal a hidden gun barrel or dagger or even a heat ray. Twist and turn at the handle to see if it can be adjusted in any manner.
If the handle doesn't move, it's unlikely that the umbrella stem contains any sort of weapon. But the skin of the umbrella itself could work as a parachute, or it could even be a bullet-proof shield. Jump up and down with the umbrella open to see if it feels like it might be able to hold your weight. And to check if it's bullet proof, borrow one of the cabby's handguns and shoot it.
If it does not appear to hold your weight and if the bullet pierces the umbrella skin, then the umbrella cannot protect you from steep falls or assassins. Last thing is to make sure the umbrella is not a bomb whose trigger you've activated via your testing. Hold the umbrella to your ear and listen for ticking or beeping, and smell it for any hint of plutonium.
If that all checks out, head back to the taxi and have the cabby take you where you need to go.
"That thing a piece of high tech weaponry or is it just�" he'll ask you.
"It's just the thing I need to keep me dry," tell the cabby. The cabby will laugh hysterically and he'll tell you that you are a piece of work.
Happy Super Umbrella Day!