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 the generated data for a specified number of entries.
  assert generate_sample_data(3)
  assert generate_sample_data(5)
output: def generate_sample_data(num_entries):
      from faker import Faker
      fake = Faker()
      for _ in range(num_entries):
          name = fake.name()
          email = fake.email()
          age = fake.random_int(min=18, max=65)
          print(f"{name}, {email}, {age}")