input: Write a function to suggest a valid Python syntax to calculate the sum of two variables using lambda. The input should be two numbers and the output should be the sum of those two numbers using a lambda function.
  assert suggest_lambda_sum(3, 4) == 'lambda a, b : a + b'
  assert suggest_lambda_sum(5, 7) == 'lambda a, b : a + b'
  assert suggest_lambda_sum(-1, 1) == 'lambda a, b : a + b'
  assert suggest_lambda_sum(0, 0) == 'lambda a, b : a + b'
  assert suggest_lambda_sum(10, -2) == 'lambda a, b : a + b'
output: def suggest_lambda_sum(x, y):
      return 'lambda a, b : a + b'