input: Write a python function to serialize a list of dictionaries into a JSON string.
  assert serialize_data([{'name':'John', 'age':30}, {'name':'Paul', 'age':22}]) == '[{"name": "John", "age": 30}, {"name": "Paul", "age": 22}]'
  assert serialize_data([{'name':'Alice', 'age':25}, {'name':'Bob', 'age':28}]) == '[{"name": "Alice", "age": 25}, {"name": "Bob", "age": 28}]'
  assert serialize_data([{'name':'Charlie', 'age':35}]) == '[{"name": "Charlie", "age": 35}]'
output: import json
  
  def serialize_data(data):
      return json.dumps(data)