input: Write a function to convert a given Python function to a C# function. The given Python function calculates the power of a number using recursion. The C# function should have the same functionality.
  public int Power(int x, int y)
  {
      if (y == 0)
      {
          return 1;
      }
      else
      {
          return x * Power(x, y - 1);
      }
  }
  assert Power(2, 3) == 8
  assert Power(5, 0) == 1
  assert Power(0, 5) == 0
  assert Power(3, 2) == 9
  assert Power(1, 10) == 1
output: public int Power(int x, int y)
  {
      if (y == 0)
      {
          return 1;
      }
      else
      {
          return x * Power(x, y - 1);
      }
  }