input: Write a python function to encode a given string to Base64.
  assert encode_to_base64("Python") == "UHl0aG9u"
  assert encode_to_base64("Hello, World!") == "SGVsbG8sIFdvcmxkIQ=="
  assert encode_to_base64("Base64 encoding") == "QmFzZTY0IGVuY29kaW5n"
output: def encode_to_base64(s):
      import base64
      encoded_bytes = base64.b64encode(s.encode('utf-8'))
      return encoded_bytes.decode('utf-8')