<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_content_type(mimetype, charset):
 """Returns the full content type string with charset for a mimetype. If the mimetype represents text, the charset parameter will be appended, otherwise the mimetype is returned unchanged. :param mimetype: The mimetype to be used as content type. :param charset: The charset to be appended for text mimetypes. :return: The content type. .. verionchanged:: 0.15 Any type that ends with ``+xml`` gets a charset, not just those that start with ``application/``. Known text types such as ``application/javascript`` are also given charsets. """

    if (
        mimetype.startswith("text/")
        or mimetype in _charset_mimetypes
        or mimetype.endswith("+xml")
    ):
        mimetype += "; charset=" + charset

    return mimetype