The Java Language Specification does not allow extra semicolons to appear between `import` statements, yet the compiler was allowing them; [JDK-8027682](https://bugs.openjdk.org/browse/JDK-8027682) fixed this.

As a result, a program like this, which previously would have compiled successfully:

    import java.util.Map;;;;
    import java.util.Set;
    class Test { }

will now generate an error:

    Test.java:1: error: extraneous semicolon
    import java.util.Map;;;;
                         ^

For backward compatibility, when compiling source versions prior to 21, a warning is generated instead of an error.