Highwire importer exceptions
| HighWireErrorException | General exception |
| HighWireFileGetContentsException | file_get_contents() failed |
| HighWireSimpleXmlException | simplexml_load_string() failed |
| HighWireApiErrorsException | Specific error returned by HighWire API |
| HighWireWpInsertPostException | wp_insert_post() failed |
| HighWireWpInsertTermException | wp_insert_term() failed |
| HighWireHtmlMissingMetaHwIdentifier | No HW.identifier meta |
| HighWirePubDateException | No publication date found in the XML |
| HighWireInvalidDateException | Invalid publication date found in the XML |
| HighWireEmptyTitleException | Missing or empty title in article XML |