def set_index(self, schema, name, fields, **index_options):
with self.transaction(**index_options) as connection:<EOL><INDENT>index_options['<STR_LIT>'] = connection<EOL>self._set_index(schema, name, fields, **index_options)<EOL><DEDENT>return True<EOL>
add an index to the table

schema -- Schema()
name -- string -- the name of the index
fields -- array -- the fields the index should be on
**index_options -- dict -- any index options that might be useful to create the index