input: Write a function to generate sample data for a web application using Python's faker library. The function should generate and print three columns of data: name, email, and age. The age should be a random integer between 18 and 60. The function should take an integer `n` as an argument which specifies the number of rows of data to generate. If `n` is not provided, the function should generate 10 rows by default.
  
  def generate_sample_data(n=10):
   from faker import Faker
   fake = Faker()
   for _ in range(n):
    print(fake.name(), fake.email(), fake.random_int(min=18, max=60))
    
  assert generate_sample_data() # Default to 10 rows
  assert generate_sample_data(5) # Should generate 5 rows
output: def generate_sample_data(n=10):
   from faker import Faker
   fake = Faker()
   for _ in range(n):
    print(fake.name(), fake.email(), fake.random_int(min=18, max=60))