@catch_nb_assignment<EOL><INDENT>def cell_start(self, cell, cell_index=None, **kwargs):<DEDENT>
if self.log_output:<EOL><INDENT>ceel_num = cell_index + <NUM_LIT:1> if cell_index is not None else '<STR_LIT>'<EOL>logger.info('<STR_LIT>'.format(ceel_num))<EOL><DEDENT>cell.metadata.papermill['<STR_LIT>'] = self.now().isoformat()<EOL>cell.metadata.papermill["<STR_LIT:status>"] = self.RUNNING<EOL>cell.metadata.papermill['<STR_LIT>'] = False<EOL>self.save()<EOL>
Set and save a cell's start state.

Optionally called by engines during execution to initialize the
metadata for a cell and save the notebook to the output path.