Why sun.nio.ch.SelChImpl is not accessable at HotSpot for Java7?

[陈雨亭]

Dear all,

I used soot to create the class M1450550406 (see next).
HotSpot for Java7 says that M1450550406 cannot access
the superinterface sun.nio.ch.SelChImpl, while HotSpot
for Java8/9 and J9 for Java8 can access. Could anyone tell
me the reason? I checked the package and believed
that  the interface is in the JRE libraries.

Yuting
**************************************************************
public class M1450550406 extends java.lang.Object implements 
sun.nio.ch.SelChImpl
{

    public static void main(java.lang.String[])
    {
        java.lang.String[] r0;
        java.io.PrintStream $r1;

        r0 := @parameter0: java.lang.String[];
        $r1 = <java.lang.System: java.io.PrintStream out>;
        virtualinvoke $r1.<java.io.PrintStream: void 
println(java.lang.String)>("Executed!");
        return;
    }
}