grib/src/main/java/ucar/nc2/grib/collection/GribCollectionMutable.java
public void close() throws java.io.IOException {

    if (indexRaf != null) {
      indexRaf.close();
      indexRaf = null;
    }
  }
public void close() throws java.io.IOException {

    if (indexRaf != null) {
      indexRaf.close();
      indexRaf = null;
    }
  }
stuff for FileCacheable