code: public void replaceRight(Pattern aPattern, String aReplacement) {
          Object lastChild = this.children.get(this.children.size() - 1);
          if (lastChild instanceof SourceNode) {
              ((SourceNode) lastChild).replaceRight(aPattern, aReplacement);
          } else if (lastChild instanceof String) {
              this.children.set(this.children.size() - 1, aPattern.matcher(((String) lastChild)).replaceFirst(aReplacement));
          } else {
              this.children.add(aPattern.matcher("").replaceFirst(aReplacement));
          }
      }
docs: Call String.prototype.replace on the very right-most source snippet. Useful for trimming whitespace from the end of a source node, etc.
  
  @param aPattern
  The pattern to replace.
  @param aReplacement
  The thing to replace the pattern with.