input: Write a python function to parse the given XML data and extract names and emails of customers.
  assert parse_customers(data) == [('John Smith', 'john@example.com'), ('Jane Doe', 'jane@example.com')]
  assert parse_customers('''<?xml version="1.0"?>
  <data>
   <customer>
   <name>Alice Brown</name>
   <email>alice@example.com</email>
   </customer>
   <customer>
   <name>Bob White</name>
   <email>bob@example.com</email>
   </customer>
  </data>''') == [('Alice Brown', 'alice@example.com'), ('Bob White', 'bob@example.com')]
output: def parse_customers(xml_data):
      import xml.etree.ElementTree as ET
      root = ET.fromstring(xml_data)
      customers = []
      for customer in root.findall('customer'):
          name = customer.find('name').text
          email = customer.find('email').text
          customers.append((name, email))
      return customers