input: Write a python function to fetch all records from a database table named 'customers' and return them.
  assert fetch_records_from_customers() == [(1, 'John Doe', 'john@example.com'), (2, 'Jane Doe', 'jane@example.com')]
  assert fetch_records_from_customers() != []
  assert isinstance(fetch_records_from_customers(), list)
output: def fetch_records_from_customers():
      import sqlite3
      connection = sqlite3.connect('example.db')
      cursor = connection.cursor()
      cursor.execute("SELECT * FROM customers")
      records = cursor.fetchall()
      connection.close()
      return records