def _hold_block(self, block_id):
managers = self.connected_managers<EOL>for manager in managers:<EOL><INDENT>if manager['<STR_LIT>'] == block_id:<EOL><INDENT>logger.debug("<STR_LIT>".format(manager['<STR_LIT>']))<EOL>self.hold_worker(manager['<STR_LIT>'])<EOL><DEDENT><DEDENT>
Sends hold command to all managers which are in a specific block

        Parameters
        ----------
        block_id : str
             Block identifier of the block to be put on hold