Bug 152430 Key can modify to empty string
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/EmbeddedImageHandle.java
}
	/**
	 * Returns the image type. The possible values are defined in
	 * {@link org.eclipse.birt.report.model.api.elements.DesignChoiceConstants}, and they
	 * are:
	 * <ul>
	 * <li><code>IMAGE_TYPE_IMAGE_JPEG</code>
	 * <li><code>IMAGE_TYPE_IMAGE_BMP</code>
	 * <li><code>IMAGE_TYPE_IMAGE_GIF</code>
	 * <li><code>IMAGE_TYPE_IMAGE_PNG</code>
	 * <li><code>IMAGE_TYPE_IMAGE_X_PNG</code>
	 * </ul>
	 * 
	 * @return the image type
	 */
	public String getType( )
	{
		return getStringProperty( EmbeddedImage.TYPE_MEMBER );
	}
	/**
	 * Sets the image type. The allowed values are defined in
	 * {@link org.eclipse.birt.report.model.api.elements.DesignChoiceConstants}, and they
	 * are:
	 * <ul>
	 * <li><code>IMAGE_TYPE_IMAGE_JPEG</code>
	 * <li><code>IMAGE_TYPE_IMAGE_BMP</code>
	 * <li><code>IMAGE_TYPE_IMAGE_GIF</code>
	 * <li><code>IMAGE_TYPE_IMAGE_PNG</code>
	 * <li><code>IMAGE_TYPE_IMAGE_X_PNG</code>
	 * </ul>