Newton's Method:
Let, the lion catch you. For every action there is equal and opposite reaction. Implies you caught lion.

Einstein Method:
Run in the direction opposite to that of the lion. Due to higher relative velocity, the lion will also run faster and will get tired soon. Now you can trap it easily.

Software Engineer Method:
Catch a cat and claim that your testing has proven that its a Lion. If anyone comes back with issues tell that you will upgrade it to Lion.

Cheers,

~Danish Sami