visitIndex method
Implementation
@override
visitIndex(IndexExpression node, {bool computeAsPattern = false}) {
dynamic val;
try {
val = visitObjectPropertyExpression(
node.object, getValueFromExpression(node.property),
computeAsPattern: computeAsPattern);
} on InvalidPropertyException catch (e) {
//ignore since obj['prop'] is fine even when prop does not exist. We just return null in that case
}
return val;
}