Bug 117148 Support Accessibility
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/attribute/Marker.java
void unsetSize( );
	/**
	 * Returns whether the value of the '{@link org.eclipse.birt.chart.model.attribute.Marker#getSize <em>Size</em>}'
	 * attribute is set. <!-- begin-user-doc --> <!-- end-user-doc -->
	 * 
	 * @return whether the value of the '<em>Size</em>' attribute is set.
	 * @see #unsetSize()
	 * @see #getSize()
	 * @see #setSize(int)
	 * @generated
	 */
	boolean isSetSize( );
	/**
	 * Returns the value of the '<em><b>Visible</b></em>' attribute. <!--
	 * begin-user-doc --> Gets whether the marker will be rendered. <!--
	 * end-user-doc --> <!-- begin-model-doc -->
	 * 
	 * Specifies whether the marker is to be rendered.
	 * 
	 * <!-- end-model-doc -->
	 * 
	 * @return the value of the '<em>Visible</em>' attribute.
	 * @see #isSetVisible()
	 * @see #unsetVisible()
	 * @see #setVisible(boolean)
	 * @see org.eclipse.birt.chart.model.attribute.AttributePackage#getMarker_Visible()
	 * @model unique="false" unsettable="true"
	 *        dataType="org.eclipse.emf.ecore.xml.type.Boolean" required="true"
	 * @generated
	 */