--- /dev/null
+<?php
+
+/**
+ * Licensed to Jasig under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for
+ * additional information regarding copyright ownership.
+ *
+ * Jasig licenses this file to you under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * PHP Version 5
+ *
+ * @file CAS/Exception.php
+ * @category Authentication
+ * @package PhpCAS
+ * @author Adam Franco <afranco@middlebury.edu>
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License 2.0
+ * @link https://wiki.jasig.org/display/CASC/phpCAS
+ */
+
+/**
+ * A root exception interface for all exceptions in phpCAS.
+ *
+ * All exceptions thrown in phpCAS should implement this interface to allow them
+ * to be caught as a category by clients. Each phpCAS exception should extend
+ * an appropriate SPL exception class that best fits its type.
+ *
+ * For example, an InvalidArgumentException in phpCAS should be defined as
+ *
+ * class CAS_InvalidArgumentException
+ * extends InvalidArgumentException
+ * implements CAS_Exception
+ * { }
+ *
+ * This definition allows the CAS_InvalidArgumentException to be caught as either
+ * an InvalidArgumentException or as a CAS_Exception.
+ *
+ * @class CAS_Exception
+ * @category Authentication
+ * @package PhpCAS
+ * @author Adam Franco <afranco@middlebury.edu>
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License 2.0
+ * @link https://wiki.jasig.org/display/CASC/phpCAS
+ *
+ */
+interface CAS_Exception
+{
+
+}
+?>
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