def select_header_content_type(self, content_types):
if not content_types:<EOL><INDENT>return '<STR_LIT:application/json>'<EOL><DEDENT>content_types = list(map(lambda x: x.lower(), content_types))<EOL>if '<STR_LIT:application/json>' in content_types:<EOL><INDENT>return '<STR_LIT:application/json>'<EOL><DEDENT>else:<EOL><INDENT>return content_types[<NUM_LIT:0>]<EOL><DEDENT>
Returns `Content-Type` based on an array of content_types provided.

:param content_types: List of content-types.
:return: Content-Type (e.g. application/json).