input: Write a function to generate sample data for a web application using Python's faker library. The output should contain three columns of data: name, email, and age. The function should print out the data for a given number of rows.
  
  def generate_sample_data(num_rows):
      from faker import Faker
      fake = Faker()
      for _ in range(num_rows):
          print(fake.name(), fake.email(), fake.random_int(min=18, max=60))
  
  assert generate_sample_data(10) is None
  assert generate_sample_data(5) is None
output: def generate_sample_data(num_rows):
      from faker import Faker
      fake = Faker()
      for _ in range(num_rows):
          print(fake.name(), fake.email(), fake.random_int(min=18, max=60))