Error code. The meaning of the code can be found on
http://openlayers.org/en/latest/errors.html (replace latest with
the version found in the OpenLayers script's header comment if a version
other than the latest is used).
Error object thrown when an assertion failed. This is an ECMA-262 Error,
extended with a code property.
Error code.
Error object thrown when an assertion failed. This is an ECMA-262 Error, extended with a
codeproperty.參閱
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error
參數: code
Error code.