Write a class called Pyramid, each pyramid has some properties: length of the base, height and number of sides (in this order!) that should always be present.
The task is to calculate the volume of the pyramid. Keep in mind the following instructions:
  - A pyramid is supposed to have 3 or 4 sides. If one tries to create a pyramid with any other number of sides, the number of sides will be fixed to 4. If this is the case, make sure to report that the input is changed.
- Assume all sides of the base of the pyramid are the same.
- The calculation of the volume should be done in the following method: getVolume()which returns a double.
- If you do not remember the formula for the volume of a pyramid: Google is your friend!
- There is no need to implement a main()method.

Adapted from Pyramid - Dark meme university