assertEquals("legacy-chart", element.getElementTypeName());
final Expression attributeExpression =
element.getAttributeExpression(AttributeNames.Core.NAMESPACE, AttributeNames.Core.VALUE);
assertNotNull(attributeExpression);
assertTrue(attributeExpression instanceof PieChartExpression);
final PieChartExpression pe = (PieChartExpression) attributeExpression;
final String dataSource = pe.getDataSource();
final Expression[] expressions =
event.getState().getFlowController().getMasterRow().getExpressionDataRow().getExpressions();
assertEquals(expressions.length, 2);
// 2 expressions: One is the validate function, the other is the chart-dataset collector.