Abstract class with a static member that can't be called

SomeAbstractClass.java

package org.example;

public abstract class SomeAbstractClass {
    
    SomeAbstractClass(){}

    /**
     * The name of the SomeAbstractClass instance.
     *
     * @return the name
     */
    public abstract String getName();

    /**
     * Concrete Implementation of SomeAbstractClass
     */
    private static final class SomeConcreteClass extends SomeAbstractClass {
        private SomeConcreteClass() {
        }

        @Override
        public String getName() {
            return "Concrete";
        }
    }

    /**
     * @return SomeAbstractClass
     */
    public static SomeAbstractClass concrete() {
        return CONCRETE;
    }

    private static final SomeAbstractClass CONCRETE;

    static {
        CONCRETE = new SomeConcreteClass();
    }
}