if (insertPos < 0 || isClassClosing) {
            throw new IllegalArgumentException("Cannot parse source file $sourceFile to apply changes")
        }
        applyChangeAt(context, text, insertPos)
    }

    protected abstract void applyChangeAt(BuildContext context, StringBuilder text, int lastMethodEndPos)

class ApplyNonAbiChangeToGroovySourceFileMutator extends AbstractGroovySourceFileMutator {
    ApplyNonAbiChangeToGroovySourceFileMutator(File sourceFile) {
        super(sourceFile)
    }

    @Override
    protected void applyChangeAt(BuildContext context, StringBuilder text, int lastMethodEndPos) {
        text.insert(lastMethodEndPos, "System.out.println(\"${context.getUniqueBuildId()}\");")
    }

class ApplyAbiChangeToGroovySourceFileMutator extends AbstractGroovySourceFileMutator {
    ApplyAbiChangeToGroovySourceFileMutator(File sourceFile) {
        super(sourceFile)
    }

    @Override
    protected void applyChangeAt(BuildContext context, StringBuilder text, int lastMethodEndPos) {
        String method = "_m${context.getUniqueBuildId()}()"
        text.insert(lastMethodEndPos + 1, "\npublic void $method { }")