Bug 315281 update copyrights for 3.6
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
}
	
	/**
	 * Configures whether this structured viewer uses an internal hash table to
	 * speeds up the mapping between elements and SWT items. This must be called
	 * before the viewer is given an input (via <code>setInput</code>).
	 * 
	 * @param enable
	 *            <code>true</code> to enable hash lookup, and
	 *            <code>false</code> to disable it
	 */
	public void setUseHashlookup(boolean enable) {
		Assert.isTrue(getInput() == null,
				"Can only enable the hash look up before input has been set");
		if (enable) {
			elementMap = newHashtable(CustomHashtable.DEFAULT_CAPACITY);
		} else {
			elementMap = null;
		}
	}
	/**
	 * Sets the comparer to use for comparing elements, or <code>null</code>
	 * to use the default <code>equals</code> and <code>hashCode</code>
	 * methods on the elements themselves.
	 * 
	 * @param comparer
	 *            the comparer to use for comparing elements or
	 *            <code>null</code>
	 */
	public void setComparer(IElementComparer comparer) {