Bug 117148 Support Accessibility
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/attribute/Marker.java
boolean isVisible( );
	/**
	 * Sets the value of the '{@link org.eclipse.birt.chart.model.attribute.Marker#isVisible <em>Visible</em>}'
	 * attribute. <!-- begin-user-doc --> Specifies whether the marker is to be
	 * rendered. <!-- end-user-doc -->
	 * 
	 * @param value
	 *            the new value of the '<em>Visible</em>' attribute.
	 * @see #isSetVisible()
	 * @see #unsetVisible()
	 * @see #isVisible()
	 * @generated
	 */
	void setVisible( boolean value );
	/**
	 * Unsets the value of the '{@link org.eclipse.birt.chart.model.attribute.Marker#isVisible <em>Visible</em>}'
	 * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
	 * 
	 * @see #isSetVisible()
	 * @see #isVisible()
	 * @see #setVisible(boolean)
	 * @generated
	 */
	void unsetVisible( );
	/**
	 * Returns whether the value of the '
	 * {@link org.eclipse.birt.chart.model.attribute.Marker#isVisible <em>Visible</em>}'
	 * attribute is set. <!-- begin-user-doc --> <!-- end-user-doc -->
	 * 
	 * @return whether the value of the '<em>Visible</em>' attribute is set.