Function get_dictionary_property 

pub(crate) fn get_dictionary_property(
    cx: &mut JSContext,
    object: HandleObject<'_>,
    property: &CStr,
    rval: MutableHandleValue<'_>,
) -> Result<bool, ()>

Get the property with name property from object. Returns Err(()) on JSAPI failure (there is a pending exception), and Ok(false) if there was no property with the given name.