A question about getClass()

Sample.java

/*
 *  A question about Java (not Kotlin!), first asked by Alexander Udalov (@udalov).
 *
 *  How many calls to getClass() does the code below make?
 *  Curiously enough, the answer is ONE (see the byte codes below).
 *
 *  Now the questions is: why does javac emit the call to getClass()?
 */

class C {
    public static void main(String[] args) {
        C c = new C();
        c.new D();
    }

    class D {  }
}

Sample.javap

public static main([Ljava/lang/String;)V
   L0
    LINENUMBER 147 L0
    NEW C
    DUP
    INVOKESPECIAL C.<init> ()V
    ASTORE 1
   L1
    LINENUMBER 148 L1
    NEW C$D
    DUP
    ALOAD 1
    DUP
    INVOKEVIRTUAL java/lang/Object.getClass ()Ljava/lang/Class;  // <---- HERE IT IS!
    POP
    INVOKESPECIAL C$D.<init> (LC;)V
    POP
   L2
    LINENUMBER 149 L2
    RETURN