diff --git a/library/log4php/LoggerNDC.php b/library/log4php/LoggerNDC.php
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--- a/library/log4php/LoggerNDC.php
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@@ -1,203 +0,0 @@
-<?php
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF 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.
- *
- * @package log4php
- */
-
-/**
- * The NDC class implements <i>nested diagnostic contexts</i>.
- *
- * NDC was defined by Neil Harrison in the article "Patterns for Logging
- * Diagnostic Messages" part of the book <i>"Pattern Languages of
- * Program Design 3"</i> edited by Martin et al.
- *
- * A Nested Diagnostic Context, or NDC in short, is an instrument
- * to distinguish interleaved log output from different sources. Log
- * output is typically interleaved when a server handles multiple
- * clients near-simultaneously.
- *
- * This class is similar to the {@link LoggerMDC} class except that it is
- * based on a stack instead of a map.
- *
- * Interleaved log output can still be meaningful if each log entry
- * from different contexts had a distinctive stamp. This is where NDCs
- * come into play.
- *
- * <b>Note that NDCs are managed on a per thread basis</b>.
- *
- * NDC operations such as {@link push()}, {@link pop()},
- * {@link clear()}, {@link getDepth()} and {@link setMaxDepth()}
- * affect the NDC of the <i>current</i> thread only. NDCs of other
- * threads remain unaffected.
- *
- * For example, a servlet can build a per client request NDC
- * consisting the clients host name and other information contained in
- * the the request. <i>Cookies</i> are another source of distinctive
- * information. To build an NDC one uses the {@link push()}
- * operation.
- *
- * Simply put,
- *
- * - Contexts can be nested.
- * - When entering a context, call <kbd>LoggerNDC::push()</kbd>
- *     As a side effect, if there is no nested diagnostic context for the
- *     current thread, this method will create it.
- * - When leaving a context, call <kbd>LoggerNDC::pop()</kbd>
- * - <b>When exiting a thread make sure to call {@link remove()}</b>
- *
- * There is no penalty for forgetting to match each
- * <kbd>push</kbd> operation with a corresponding <kbd>pop</kbd>,
- * except the obvious mismatch between the real application context
- * and the context set in the NDC.
- *
- * If configured to do so, {@link LoggerPatternLayout} and {@link LoggerLayoutTTCC}
- * instances automatically retrieve the nested diagnostic
- * context for the current thread without any user intervention.
- * Hence, even if a servlet is serving multiple clients
- * simultaneously, the logs emanating from the same code (belonging to
- * the same category) can still be distinguished because each client
- * request will have a different NDC tag.
- *
- * Example:
- *
- * {@example ../../examples/php/ndc.php 19}<br>
- *
- * With the properties file:
- *
- * {@example ../../examples/resources/ndc.properties 18}<br>
- *
- * Will result in the following (notice the conn and client ids):
- *
- * <pre>
- * 2009-09-13 19:04:27 DEBUG root conn=1234: just received a new connection in src/examples/php/ndc.php at 23
- * 2009-09-13 19:04:27 DEBUG root conn=1234 client=ab23: some more messages that can in src/examples/php/ndc.php at 25
- * 2009-09-13 19:04:27 DEBUG root conn=1234 client=ab23: now related to a client in src/examples/php/ndc.php at 26
- * 2009-09-13 19:04:27 DEBUG root : back and waiting for new connections in src/examples/php/ndc.php at 29
- * </pre>
- *
- * @version $Revision: 1350602 $
- * @package log4php
- * @since 0.3
- */
-class LoggerNDC {
-
-    /** This is the repository of NDC stack */
-    private static $stack = array();
-
-    /**
-     * Clear any nested diagnostic information if any. This method is
-     * useful in cases where the same thread can be potentially used
-     * over and over in different unrelated contexts.
-     *
-     * <p>This method is equivalent to calling the {@link setMaxDepth()}
-     * method with a zero <var>maxDepth</var> argument.
-     */
-    public static function clear() {
-        self::$stack = array();
-    }
-
-    /**
-     * Never use this method directly, use the {@link LoggerLoggingEvent::getNDC()} method instead.
-     * @return array
-     */
-    public static function get() {
-        return implode(' ', self::$stack);
-    }
-
-    /**
-     * Get the current nesting depth of this diagnostic context.
-     *
-     * @see setMaxDepth()
-     * @return integer
-     */
-    public static function getDepth() {
-        return count(self::$stack);
-    }
-
-    /**
-     * Clients should call this method before leaving a diagnostic
-     * context.
-     *
-     * <p>The returned value is the value that was pushed last. If no
-     * context is available, then the empty string "" is returned.</p>
-     *
-     * @return string The innermost diagnostic context.
-     */
-    public static function pop() {
-        if (count(self::$stack) > 0) {
-            return array_pop(self::$stack);
-        } else {
-            return '';
-        }
-    }
-
-    /**
-     * Looks at the last diagnostic context at the top of this NDC
-     * without removing it.
-     *
-     * <p>The returned value is the value that was pushed last. If no
-     * context is available, then the empty string "" is returned.</p>
-     * @return string The innermost diagnostic context.
-     */
-    public static function peek() {
-        if (count(self::$stack) > 0) {
-            return end(self::$stack);
-        } else {
-            return '';
-        }
-    }
-
-    /**
-     * Push new diagnostic context information for the current thread.
-     *
-     * <p>The contents of the <var>message</var> parameter is
-     * determined solely by the client.
-     *
-     * @param string $message The new diagnostic context information.
-     */
-    public static function push($message) {
-        array_push(self::$stack, (string)$message);
-    }
-
-    /**
-     * Remove the diagnostic context for this thread.
-     */
-    public static function remove() {
-        LoggerNDC::clear();
-    }
-
-    /**
-     * Set maximum depth of this diagnostic context. If the current
-     * depth is smaller or equal to <var>maxDepth</var>, then no
-     * action is taken.
-     *
-     * <p>This method is a convenient alternative to multiple
-     * {@link pop()} calls. Moreover, it is often the case that at
-     * the end of complex call sequences, the depth of the NDC is
-     * unpredictable. The {@link setMaxDepth()} method circumvents
-     * this problem.
-     *
-     * @param integer $maxDepth
-     * @see getDepth()
-     */
-    public static function setMaxDepth($maxDepth) {
-        $maxDepth = (int)$maxDepth;
-        if (LoggerNDC::getDepth() > $maxDepth) {
-            self::$stack = array_slice(self::$stack, 0, $maxDepth);
-        }
-    }
-}