http://hamcrest.org/JavaHamcrest/javadoc/
http://hamcrest.org/JavaHamcrest/javadoc/1.3/
http://hamcrest.org/JavaHamcrest/javadoc/2.0.0.0/

\--- junit:junit:4.12
     \--- org.hamcrest:hamcrest-core:1.3

http://hamcrest.org/JavaHamcrest/javadoc/1.3/org/hamcrest/core/IsNot.html