input: Write a function to suggest a valid Python syntax to calculate the sum of two variables using a lambda function. The function should take two input variables and return the result of their sum. Provide one test case with the given input and output.
  assert suggest_lambda_sum(3, 4) == 7
  print(suggest_lambda_sum(3, 4))
output: suggest_lambda_sum = lambda x, y: x + y