final Builder builder = Settings.builder()
                .putList("http.hosts", hosts)
                .put("processors", fessConfig.getCrawlerHttpProcessors())
                .put("http.heartbeat_interval", fessConfig.getFesenHeartbeatInterval());
        final String username = fessConfig.getFesenUsername();

    }

    /**
     * Timer task for destroying processes that exceed their timeout.
     * Handles graceful and forceful termination of thumbnail generation processes.
     */
    protected static class ProcessDestroyer extends TimerTask {

        /** The process to monitor and destroy. */
        private final Process p;

        /** The input stream thread reading process output. */
        private final InputStreamThread ist;

     */
    public PermissionHelper() {
        // Default constructor
    }

    /**
     * Encodes a permission string into a search role format.
     * Processes user, group, and role prefixes along with allow/deny prefixes.
     *
     * @param value the permission string to encode
     * @return the encoded permission string, or null if the input is blank or invalid
     */

        } catch (final Exception e) {
            if (logger.isDebugEnabled()) {
                logger.debug("Failed to process a ping request.", e);
            }
            writeJsonResponse(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e);
        }
    }

    /**
     * Processes a search request.
     * @param request The HTTP request.
     * @param response The HTTP response.

		(op1 << 20) | // MCR/MRC
		((int64(bits) ^ arm.C_SCOND_XOR) << 28) | // scond
		((x0 & 15) << 8) | //coprocessor number
		((x1 & 7) << 21) | // coprocessor operation
		((x2 & 15) << 12) | // ARM register
		((x3 & 15) << 16) | // Crn
		((x4 & 15) << 0) | // Crm
		((x5 & 7) << 5) | // coprocessor information
		(1 << 4) /* must be set */
	return offset, arm.AMRC, true
}

                    logger.debug("Failed to access UserInfo cache.", e);
                }
            }
        }
        return OptionalEntity.empty();
    }

    /**
     * Processes the search log queue.
     *
     * @param queue The search log queue.
     */
    protected void processSearchLogQueue(final Queue<SearchLog> queue) {

        }
    }

    /**
     * Processes allowed SIDs (Security Identifiers) and adds them to the SID set.
     * If the SID is a group, it recursively processes all group members.
     *
     * @param file the SMB file
     * @param sid the SID to process
     * @param sidSet the set of SIDs to add to
     */

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.
* Then it passes the **request** to be processed by the rest of the application (by some *path operation*).

//msgp:ignore rateMeasurement

type rateMeasurement struct {
	lock                 sync.Mutex
	bytesSinceLastWindow uint64    // Total bytes since last window was processed
	startTime            time.Time // Start time for window
	expMovingAvg         float64   // Previously calculated exponential moving average
}

Si revisas el "administrador de tareas" o "monitor del sistema" (o herramientas similares) en tu sistema operativo, podrás ver muchos de esos procesos en ejecución.

Y, por ejemplo, probablemente verás que hay múltiples procesos ejecutando el mismo programa del navegador (Firefox, Chrome, Edge, etc.). Normalmente ejecutan un proceso por pestaña, además de algunos otros procesos extra.