Esto es muy útil cuando necesitas:

* Tener lógica compartida (la misma lógica de código una y otra vez).
* Compartir conexiones a bases de datos.
* Imponer seguridad, autenticación, requisitos de roles, etc.
* Y muchas otras cosas...

Todo esto, mientras minimizas la repetición de código.

## Primeros Pasos

Veamos un ejemplo muy simple. Será tan simple que no es muy útil, por ahora.

        public MockSuggestDeleteResponse deleteQueryWords() {
            return new MockSuggestDeleteResponse();
        }

        public void indexFromSearchWord(String searchWord, String[] fields, String[] tags, String[] roles, int weight, String[] langs) {
            // Mock implementation
        }

        public void deleteElevateWord(String word, boolean apply) {
            // Mock implementation
        }

            officeManager.stop();
        } catch (final OfficeException e) {
            throw new CrawlerSystemException("Failed to stop officeManager.", e);
        }
    }

    /**
     * Adds a conversion rule for mapping input file extensions to output extensions.
     *
     * @param inExt the input file extension
     * @param outExt the output file extension
     */

 * intermediate certificate, "Entrust Certification Authority - L1M". The intermediate certificate
 * is used to verify the signature of the "www.squareup.com" certificate.
 *
 * This roles are reversed for client authentication. In that case the client has a private key and
 * a chain of certificates. The server uses a set of trusted root certificates to authenticate the

		case "content-length":
			// Signature-V4 spec excludes Content-Length from signed headers list for signature calculation.
			// But some clients deviate from this rule. Hence we consider Content-Length for signature
			// calculation to be compatible with such clients.
			extractedSignedHeaders.Set(header, strconv.FormatInt(r.ContentLength, 10))
		default:
			return nil, ErrUnsignedHeaders

	"uploadId",
	"uploads",
	"versionId",
	"versioning",
	"versions",
	"website",
}

// Signature and API related constants.
const (
	signV2Algorithm = "AWS"
)

// AWS S3 Signature V2 calculation rule is give here:
// http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#RESTAuthenticationStringToSign
func doesPolicySignatureV2Match(formValues http.Header) (auth.Credentials, APIErrorCode) {

                    appendJson("referer", entity.getReferer(), buf).append(',');
                    appendJson("languages", entity.getLanguages(), buf).append(',');
                    appendJson("roles", entity.getRoles(), buf).append(',');
                    appendJson("user-agent", entity.getUserAgent(), buf).append(',');
                    appendJson("client-ip", entity.getClientIp(), buf).append(',');

font-size($display3-size);\n  font-weight: $display3-weight;\n  line-height: $display-line-height;\n}\n.display-4 {\n  @include font-size($display4-size);\n  font-weight: $display4-weight;\n  line-height: $display-line-height;\n}\n\n\n//\n// Horizontal rules\n//\n\nhr {\n  margin-top: $hr-margin-y;\n  margin-bottom: $hr-margin-y;\n  border: 0;\n  border-top: $hr-border-width solid $hr-border-color;\n}\n\n\n//\n// Emphasis\n//\n\nsmall,\n.small {\n  @include font-size($small-font-size);\n  font-weight:...

chable\":true,\"aggregatable\":true,\"readFromDocValues\":true},{\"name\":\"responseTime\",\"type\":\"number\",\"esTypes\":[\"long\"],\"count\":0,\"scripted\":false,\"searchable\":true,\"aggregatable\":true,\"readFromDocValues\":true},{\"name\":\"roles\",\"type\":\"string\",\"esTypes\":[\"keyword\"],\"count\":0,\"scripted\":false,\"searchable\":true,\"aggregatable\":true,\"readFromDocValues\":true},{\"name\":\"searchField._default\",\"type\":\"string\",\"esTypes\":[\"keyword\"],\"count\":0,\"scr...

			 <!--
			 "node.name":"search_engine",
			 "discovery.seed_hosts":"search_engine",
			 "cluster.initial_cluster_manager_nodes":"search_engine",
			 "node.roles":"cluster_manager,data,ingest,ml",
			 -->
			 "indices.breaker.total.limit":"100%",
			 "action.auto_create_index":"-*"}
		</property>
		<!-- Dictionaries -->
		<postConstruct name="addConfigFile">