anchor.diff:  .The setup
   [source,yml]
   ----
  -spring.sleuth:
  -  baggage-keys:
  -    - baz
  -    - bizarrecase
  -  propagation-keys:
  -    - foo
  -    - upper_case
  +Unresolved directive in intro.adoc - include::{project-root}/spring-cloud-sleuth-core/src/test/resources/application-baggage.yml[indent=0]
   ----
   
   .The code
   [source,java]
   ----
  -initialSpan.tag("foo",
  -		ExtraFieldPropagation.get(initialSpan.context(), "foo"));
  -initialSpan.tag("UPPER_CASE",
  -		ExtraFieldPropagation.get(initialSpan.context(), "UPPER_CASE"));
  +Unresolved directive in intro.adoc - include::{project-root}/spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/multiple/MultipleHopsIntegrationTests.java[tags=baggage_tag,indent=0]
   ----
   
   [[sleuth-adding-project]]
  
positive.code: 
  [source,java]
  ----
  
  @Configuration
  protected static class MyConfig {
  
  	@Bean(ZipkinAutoConfiguration.REPORTER_BEAN_NAME)
  	Reporter<zipkin2.Span> myReporter() {
  		return AsyncReporter.create(mySender());
  	}
  
  	@Bean(ZipkinAutoConfiguration.SENDER_BEAN_NAME)
  	MySender mySender() {
  		return new MySender();
  	}
  
  	static class MySender extends Sender {
  
  		private boolean spanSent = false;
  
  		boolean isSpanSent() {
  			return this.spanSent;
  		}
  
  		@Override
  		public Encoding encoding() {
  			return Encoding.JSON;
  		}
  
  		@Override
  		public int messageMaxBytes() {
  			return Integer.MAX_VALUE;
  		}
  
  		@Override
  		public int messageSizeInBytes(List<byte[]> encodedSpans) {
  			return encoding().listSizeInBytes(encodedSpans);
  		}
  
  		@Override
  		public Call<Void> sendSpans(List<byte[]> encodedSpans) {
  			this.spanSent = true;
  			return Call.create(null);
  		}
  
  	}
  
  }
  
  ----
  
  == Additional Resources
  
negative.code: 
  [source,java]
  ----
  Unresolved directive in intro.adoc - include::{project-root}/spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/multiple/MultipleHopsIntegrationTests.java[tags=baggage,indent=0]
  ----
  
  ===== Baggage versus Span Tags
  