legacy/src/main/java/ucar/nc2/NetcdfFileWriteable.java
@Override
  public synchronized void close() throws java.io.IOException {
    if (spiw != null) {
      flush();
      spiw.close();
      spiw = null;
    }
    spi = null;
  }
@Override
  public synchronized void close() throws java.io.IOException {
    if (spiw != null) {
      flush();
      spiw.close();
      spiw = null;
    }
    spi = null;
  }
close the file.
@throws IOException if I/O error