const char * const config_element_control_uri = "control_uri";
const char * const config_element_data_uri = "data_uri";
const char * const config_element_max_size = "max_size";
const char * const config_element_control_uri = "control_uri";
const char * const config_element_data_uri = "data_uri";
const char * const config_element_max_size = "max_size";