PhongMaterial.toString() method produces StackOverflowError

The following line of code causes StackOverflowError:

new PhongMaterial().toString();

Caused by: java.lang.StackOverflowError
at java.util.Arrays.copyOf(Arrays.java:2367)
at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:130)
at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:114)
at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:415)
at java.lang.StringBuilder.append(StringBuilder.java:132)
at javafx.scene.paint.PhongMaterial.toString(PhongMaterial.java:356)
at java.lang.String.valueOf(String.java:2854)
at java.lang.StringBuilder.append(StringBuilder.java:128)
at javafx.beans.property.ObjectPropertyBase.toString(ObjectPropertyBase.java:197)
at java.lang.String.valueOf(String.java:2854)
at java.lang.StringBuilder.append(StringBuilder.java:128)
at javafx.scene.paint.PhongMaterial.toString(PhongMaterial.java:356)
at java.lang.String.valueOf(String.java:2854)
at java.lang.StringBuilder.append(StringBuilder.java:128)
at javafx.beans.property.ObjectPropertyBase.toString(ObjectPropertyBase.java:197)