update ref

thangpt2019 · thangpt2019 · commit 64fa7180ec79 · 2017-12-31T23:27:47.000+09:00
diff --git a/java9-language-features-examples/README.md b/java9-language-features-examples/README.md
@@ -12,6 +12,7 @@ Demonstration for:
 
 [Java 9 HTTP 2 Client API Example](https://howtoprogram.xyz/2017/10/19/java-9-http-2-client-api-example/)
 
+[Create An Immutable Set In Java 9 By Static Factory Methods](https://howtoprogram.xyz/2017/12/31/create-immutable-set-java-9-static-factory-methods/)
 
 
 ## Prerequisites:

Original file line number	Diff line number	Diff line change
`@@ -12,6 +12,7 @@ Demonstration for:`
`12`	`12`
`13`	`13`	`[Java 9 HTTP 2 Client API Example](https://howtoprogram.xyz/2017/10/19/java-9-http-2-client-api-example/)`
`14`	`14`
	`15`	`+[Create An Immutable Set In Java 9 By Static Factory Methods](https://howtoprogram.xyz/2017/12/31/create-immutable-set-java-9-static-factory-methods/)`
`15`	`16`
`16`	`17`
`17`	`18`	`## Prerequisites:`