code: @Override
  	public Set<PropertyKey> getPropertyKeys(final String propertyView) {
  
  		// check for custom view in content-type field
  		if (securityContext != null && securityContext.hasCustomView()) {
  
  			final Set<PropertyKey> keys = new LinkedHashSet<>(StructrApp.getConfiguration().getPropertySet(entityType, PropertyView.All));
  			final Set<String> customView = securityContext.getCustomView();
  
  			for (Iterator<PropertyKey> it = keys.iterator(); it.hasNext();) {
  				if (!customView.contains(it.next().jsonName())) {
  
  					it.remove();
  				}
  			}
  
  			return keys;
  		}
  
  		// this is the default if no application/json; properties=[...] content-type header is present on the request
  		return StructrApp.getConfiguration().getPropertySet(entityType, propertyView);
  	}
docs: Returns the property set for the given view as an Iterable.
  
  @param propertyView
  @return the property set for the given view