private String instrument(final int lineNumber, final ScriptData data) {
final Parser parser = new Parser();
final String sourceUriAsString = data.getSourceUriAsString();
final AstRoot root = parser.parse(data.getSourceCode(), sourceUriAsString, lineNumber);
root.visit(new InstrumentingNodeVisitor(data, lineNumber - 1));
final String treeSource = root.toSource();
final StringBuilder buf = new StringBuilder(
INITIALIZING_CODE.length() +
data.getNumberOfStatements() * ARRAY_INITIALIZER.length() +