private void renderValidationMetadataMap(FacesContext context, Map<String, Object> metadata) throws IOException {
        if (metadata == null || metadata.isEmpty()) {
            return;
        }

        ResponseWriter writer = context.getResponseWriter();

        for (Map.Entry<String, Object> entry : metadata.entrySet()) {
            String key = entry.getKey();
            Object value = entry.getValue();

            if (value != null) {
                writer.writeAttribute(key, value, null);
            }
        }
    }
Renders a hidden input field commonly use for holding state for a component.

@param context the FacesContext
@param id the id of the hidden field
@param value the value of the hidden field, can be NULL
@param disabled whether the hidden field is disabled or not
@throws IOException if any error occurs
primefaces/src/main/java/org/primefaces/renderkit/CoreRenderer.java