code: public boolean hasInfo() throws IOException {
          // Read a line, then skip back
          mark(1024);
          String[] component = readTrimmedLine().split(" +");
          reset();
  
          return component[0].equalsIgnoreCase("%%MatrixMarket");
      }
docs: Checks if a Matrix Market header is present ("%%MatrixMarket")
  
  @return True if a header was found, else false
  @throws IOException