Bug 163018 An error extension will lead the report contain chart can't be opened and can not new a report.
Details: An error extension will lead the report contain chart can't open In org.eclipse.birt.report.tests.model has an error extension. When run the birt use workbenck, the report contain chart can't be opened and it can not new a report.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ElementDefn.java
* Returns the method definition list of this element definition and parent
	 * definition. Each one is the instance of <code>PropertyDefn</code>.
	 * 
	 * @return the method definition list.
	 */
	public List getMethods( )
	{
		return getPropertyListWithType( getProperties( ),
				IPropertyType.SCRIPT_TYPE );
	}
	/**
	 * Returns the method definition list of this element definition. Each one
	 * is the instance of <code>PropertyDefn</code>.
	 * 
	 * @return the method definition list.
	 */
	public List getLocalMethods( )
	{
		return getPropertyListWithType( getLocalProperties( ),
				IPropertyType.SCRIPT_TYPE );
	}
	/**
	 * Returns the expression property definition list of this element
	 * definition and parent definition. Each one is the instance of
	 * <code>PropertyDefn</code>.
	 * 
	 * @return the expression property definition list.
	 */
	public List getExpressions( )
	{