Kata

In this kata we mix some tasty fruit juice. We can add some components with certain amounts. Sometimes we pour out a bit of our juice. Then we want to find out, which concentrations our fruit juice has.

Example:

• You take an empty jar for your juice
• Whenever the jar is empty, the concentrations are always 0
• Now you add 200 units of apple juice
• And then you add 200 units of banana juice
• Now the concentration of apple juice is 0.5 (50%)
• Then you pour out 200 units
• The concentration of apple juice is still 50%
• Then you add 200 units of apple juice again
• Now the concentration of apple juice is 0.75, while the concentration of banana juice is only 0.25 (300 units apple juice + 100 units banana juice)

Complete the functions in order to provide this functionality. The test code for the example above can be found in the test fixture.