input: def customer_search_cli(customer_name: str) -> None:
      """
      Create a command-line application in Python that stores customer data and allows users to query by customer name.
      The application should accept a customer name as a command-line argument and print the corresponding customer data.
      If a customer is not found, it should print a message indicating that.
  
      Example:
      >>> customer_search_cli("John Doe")
      [Customer Data for John Doe]
      >>> customer_search_cli("Jane Smith")
      [Customer Data for Jane Smith]
      >>> customer_search_cli("Unknown")
      "Customer not found."
      """
output:     customers = {
          "John Doe": "[Customer Data for John Doe]",
          "Jane Smith": "[Customer Data for Jane Smith]"
      }
      
      if customer_name in customers:
          print(customers[customer_name])
      else:
          print("Customer not found.")