queue.add(task);
        return;
      }

      oldRunCount = workerRunCount;

      // If the worker is not yet running, the delegate Executor might reject our attempt to start
      // it. To preserve FIFO order and failure atomicity of rejected execution when the same
      // Runnable is executed more than once, allocate a wrapper that we know is safe to remove by

		names = append(names, embeddedValues(relations)...)
	}
	return names
}

// preloadEntryPoint enters layer by layer. It will call real preload if it finds the right entry point.
// If the current relationship is embedded or joined, current query will be ignored.
//
//nolint:cyclop

But first, let's check some small concepts.

## In a hurry?

If you don't care about any of these terms and you just need to add security with authentication based on username and password *right now*, skip to the next chapters.

## OAuth2

OAuth2 is a specification that defines several ways to handle authentication and authorization.

It is quite an extensive specification and covers several complex use cases.

    // GWT's ConcurrentHashMap is a wrapper around HashMap, but it rejects null keys, which matches
    // the behaviour of the non-GWT implementation of newConcurrentHashSet().
    // On the other hand HashSet might be better for code size if apps aren't
    // already using Collections.newSetFromMap and ConcurrentHashMap.
    return Collections.newSetFromMap(new ConcurrentHashMap<E, Boolean>());
  }

                .readAttributes();
        assertThat(attributes.permissions()).containsExactly(OWNER_READ, OWNER_WRITE);
      }
    }
    out.close();

    // Check that source returns the right data
    assertTrue(Arrays.equals(data, source.read()));

    // Make sure that reset deleted the file
    out.reset();
    if (file != null) {
      assertFalse(file.exists());
    }
  }

				<div class="col">
					${item}
				</div>
			</div>
		</c:forEach>
		<c:choose>
			<c:when test="${f:h(allRecordCount) != 0}">
				<jsp:include page="searchResults.jsp" />
				<div class="text-right">
					<a href="#"><la:message key="labels.footer_back_to_top" /></a>
				</div>
			</c:when>
			<c:otherwise>
				<jsp:include page="searchNoResult.jsp" />
			</c:otherwise>
		</c:choose>
	</main>

          canUseHeaderValue = false
        } else {
          headerValue = value
        }
      }
      name.equals("Pragma", ignoreCase = true) -> {
        // Might specify additional cache-control params. We invalidate just in case.
        canUseHeaderValue = false
      }
      else -> {
        continue@loop
      }
    }

    var pos = 0

				<div class="col">
					${item}
				</div>
			</div>
		</c:forEach>
		<c:choose>
			<c:when test="${f:h(allRecordCount) != 0}">
				<jsp:include page="searchResults.jsp" />
				<div class="text-right">
					<a href="#"><la:message key="labels.footer_back_to_top" /></a>
				</div>
			</c:when>
			<c:otherwise>
				<jsp:include page="searchNoResult.jsp" />
			</c:otherwise>
		</c:choose>
	</main>

  // values are specific to the node & CRI configuration.  It is assumed that
  // all handlers are available on every node, and handlers of the same name are
  // equivalent on every node.
  // For example, a handler called "runc" might specify that the runc OCI
  // runtime (using native Linux containers) will be used to run the containers
  // in a pod.
  // The runtimeHandler must be lowercase, conform to the DNS Label (RFC 1123)

You would also need a file `__init__.py` as you saw in [Bigger Applications - Multiple Files](../tutorial/bigger-applications.md){.internal-link target=_blank}.

///

## Settings in a dependency

In some occasions it might be useful to provide the settings from a dependency, instead of having a global object with `settings` that is used everywhere.