@header.setter<EOL><INDENT>def header(self, headers):<DEDENT>
if isinstance(headers, list):<EOL><INDENT>for h in headers:<EOL><INDENT>self.add_header(h)<EOL><DEDENT><DEDENT>else:<EOL><INDENT>self.add_header(headers)<EOL><DEDENT>
Add headers to the email

        :param value: A list of Header objects or a dict of header key/values
        :type value: Header, list(Header), dict