input: Write a function to generate a Python script that contains a function with two parameters and returns the sum of the two parameters. The generated function should have the following signature and description:
  
  def add(x, y): 
   """Returns the sum of x and y"""
   return x + y
  
  assert add(3, 4) == 7
  assert add(-1, 5) == 4
  assert add(0, 0) == 0
  assert add(-3, -2) == -5
  assert add(10, -10) == 0
output: def add(x, y): 
   """Returns the sum of x and y"""
   return x + y