code: public static List<StackLine> getStackLines(SrcTree srcTree,
              StackTraceElement[] elements, LineReplacer replacer) {
          List<StackLine> stackLines = new ArrayList<>(elements.length);
          for (StackTraceElement element : elements) {
              StackLine stackLine = getStackLine(srcTree, element, replacer);
              if (stackLine != null) {
                  stackLines.add(stackLine);
              }
          }
          return stackLines;
      }
docs: gap line (the line out of SrcTree) is skipped