docs: def modify_process_properties(self, key_value_map={}, pid=None):
          '''
          modify_process_properties(self, key_value_map={}, pid=None)
  
          Modify process output properties.
          Please note that process property key provided must be declared as an output property in the relevant service specification.
  
          :Parameters:
          * *key_value_map* (`object`) -- key value map with process properties to modify
          * *pid* (`string`) -- Identifier of an existing process
  
          :Example:
          .. code-block:: python
  
             process_output_properties = {"my_output_param" : "1"}
             pid = opereto_client.create_process(service='simple_shell_command', title='Test simple shell command service')
             opereto_client.modify_process_properties(process_output_properties, pid)
  
          '''
          pid = self._get_pid(pid)
          request_data={"properties": key_value_map}
          return self._call_rest_api('post', '/processes/'+pid+'/output', data=request_data, error='Failed to output properties')