def format(self, conf=None):
if self.ac:<EOL><INDENT>ref = self.ac<EOL>if self.gene:<EOL><INDENT>ref += "<STR_LIT:(>" + self.gene + "<STR_LIT:)>"<EOL><DEDENT>ref += "<STR_LIT::>"<EOL><DEDENT>else:<EOL><INDENT>ref = "<STR_LIT>"   <EOL><DEDENT>if self.posedit is not None:<EOL><INDENT>posedit = self.posedit.format(conf)<EOL><DEDENT>else:<EOL><INDENT>posedit = "<STR_LIT:?>"<EOL><DEDENT>typo = "<STR_LIT>".format(type=self.type, posedit=posedit)<EOL>return ref + typo<EOL>
Formatting the stringification of sequence variants

        :param conf: a dict comprises formatting options. None is to use global settings.

        See :class:`hgvs.config`.