String termText = nextToken.term();
if (termText.contains(oldPrefix))
{
// the term contains the character we're looking for - replace all occurrences
String keyword = termText.replace(oldPrefix, newPrefix);
nextToken.reinit(keyword, 0, keyword.length());
if (keyword.startsWith(newPrefix))
{
// and it started with the keyword
if (!extractedKeywords.contains(keyword))