@hep.over('<STR_LIT>', '<STR_LIT>')<EOL>@utils.for_each_value<EOL>def titles(self, key, value):
if not key.startswith('<STR_LIT>'):<EOL><INDENT>return {<EOL>'<STR_LIT:source>': value.get('<STR_LIT>'),<EOL>'<STR_LIT>': value.get('<STR_LIT:b>'),<EOL>'<STR_LIT:title>': value.get('<STR_LIT:a>'),<EOL>}<EOL><DEDENT>self.setdefault('<STR_LIT>', []).insert(<NUM_LIT:0>, {<EOL>'<STR_LIT:source>': value.get('<STR_LIT>'),<EOL>'<STR_LIT>': value.get('<STR_LIT:b>'),<EOL>'<STR_LIT:title>': value.get('<STR_LIT:a>'),<EOL>})<EOL>
Populate the ``titles`` key.