Question
Element with readOnly property is under elements in the PDF
When a checkbox or any element has a read only it will be under the elements in the pdf, 
As you see, the black half circle is under a square that the PDF have from the start, if the checkbox has readOnly false it will be above the square and that's the right thing, but when gets the readOnly true it will be under, why is this happening?, there is a property from the z axis to put them above?
