Bug 152430 Key can modify to empty string
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/CustomColorHandle.java
/*******************************************************************************
 * Copyright (c) 2004 Actuate Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Actuate Corporation  - initial API and implementation
 *******************************************************************************/
package org.eclipse.birt.report.model.api;
import org.eclipse.birt.report.model.api.elements.structures.CustomColor;
import org.eclipse.birt.report.model.api.util.ColorUtil;
import org.eclipse.birt.report.model.api.util.StringUtil;
import org.eclipse.birt.report.model.core.Module;
import org.eclipse.birt.report.model.elements.Library;
/**
 * Represents the handle of custom color. The developer can define a set of
 * custom color names as part of the design. The developer can then reference
 * these names within properties.
 * <p>
 * Every custom color has three parts: a display name, an internal name and a
 * color value.
 * <p>
 * <dl>
 * <dt><strong>Name </strong></dt>
 * <dd>a custom color has a unique and required name, so the user can use the